Kirstie Allsopp: 'They say 'she is retrograde, backward-thinking'. F**k off, I am a feminist'

Kirstie Allsopp is cross. Really cross. So cross, in fact, that her cheeks are tinted a bloody red and her voice crackles as if she might cry. "I'm sorry, we have talked about Fill Your House For Free..." she turns to the press officer overseeing the launch of the new show she is supposed to be promoting, before turning back to me. "But the thing is, I've got to be honest. I'm fucking angry. More angry than I have been in the entire time I've had this job and this public profile, because there are women out there who are writing – and they are women, they are not men – they are writing things about me that are vile, derogatory and deeply, deeply personal and it's wrong, it's completely wrong. They are lying to the next generation of women and I don't understand why."

It is five days since Allsopp gave an interview in which she said – "with a degree of humour" and in the context of a conversation about housing, she wants it known – that if she had a daughter, which she doesn't (though she has two sons, the first of which she had at the age of 35) then she would tell her not to go to university, but instead to find a nice boyfriend, get knocked up by the age of 27 and settle down. Controversial, maybe, but comments the 42-year-old, who made her name as the straight-talking property presenter alongside Phil Spencer on Location, Location, Location, following careers as an interior designer, ad-seller at Country Living magazine, and co-founder of property search company Kirmir, is now at pains to defend. "This is something people don't want to talk about, but we need to talk about it. I have friends who either haven't managed [to get pregnant] or who have had problems in their pregnancies, or who had only one child when they wanted more, and I have seen it again and again and again because women have left it too late, and it's one of the things that I've seen that has caused the most pain..."

She has, she says, received messages in the past week from people telling her the issue of dwindling fertility in older women isn't something she should have brought up because women are all too aware of the ticking clock. She disagrees: "Everybody does not know. And you know what? This week lots of people have direct-messaged me – high-profile people who haven't had the guts to say it publicly – to say you're right. I'm really very cross that so many people have been so rude and so angry with me, because actually there are people who don't know, and it's frightened me, it's made me feel that the people who inform women are wanting to shut this conversation down."

Today, at least, Allsopp will not be silenced. Not by the haters, not by her publicist, and certainly not before she's also clarified her comments about women not bothering going to university. "I didn't say all women! I never said all! All I said was women have a window of about 15 years in which to do many things. And can we please remember that today, getting a degree means borrowing a considerable amount of money? Which people have totally ignored in all the responses I've had: 'I am responding to Kirstie who personally attacked me and my choices'. When I say 'Think about university', I'm not saying 'Think about tertiary education', I'm saying 'Think that you're going to be in a load of debt. So please, don't spend £28,000 on a degree unless it is going to benefit you. And to borrow that kind of money and find that actually it is no good to you, when you need to get a deposit for a house, and nobody's even said anything about pensions – you're supposed to start your pensions way before!' And all I said was that." She takes a sharp intake of breath, pauses, and then is off once more.

"And I've had people saying I'm taking women back to the Dark Ages, that I'm anti-feminist. It is f***ing b****cks. I am an independent woman with my own company who encourages other women. Anyone who knows Phil [Spencer, her co-presenter on Location, Location, Location] and I, and me and Ben [Andersen, her boyfriend] knows the dynamic. Yes, I happen to wear skirts, because I have SMALL ankles and a LARGE arse. It's not a comment on women in trousers. Sometimes I think it's a bit unfortunate, because for a lot of people they see this skirt-wearing, posh, privileged..." At this point she starts throwing her arms around marking an imaginary register. "Privileged? Yes, 100 per cent, I'll tick that – tick, tick, tick, tick, tick – they see all that and then they say 'Well therefore she is retrograde, right-wing, backward-thinking, anti-feminist'. They say 'You can't call yourself a feminist'. I can. I CAN! I'm getting a T-shirt: 'F**K OFF, I AM A FEMINIST'."

To highlight the breadth of the abuse that has characterised the past week, Allsopp reads out, unprompted, highlights. One email is from a woman citing advice Allsopp once gave in a women's magazine article entitled 'The Perfect Christmas', which suggested you keep £60 worth of Urban Outfitters' vouchers in a draw in case friends with teenagers drop in unexpectedly. She reads the message aloud: "'She was, I wrote [at the time], completely out of touch with the real world'... Did I say hand over the entire 60 quid?! No, you get it in small denominations and depending on whether your child is your nephew or some random child who seems to be slightly low on presents, you distribute accordingly." She huffs. "I should have stopped reading, OK? At that point. I should have realised if that woman took the time to email because I said have some vouchers, which seems to be quite sensible..."

She continues regaling selected extracts: "'There's the way she makes finding a nice boyfriend something she might send Phil Spencer to do when he has a spare hour or two – although I would totally trust Phil Spencer's taste in men'. I think she's saying she thinks Phil is gay – which is something I say A LOT..." she adds with a cackle before turning to me and her right-hand woman, Beth, who is busy googling the pronunciation of the word Plaistow, the location of the first episode of Kirstie's Fill Your House For Free, the second series of a show that sees Kirstie help homeowners who don't have any furniture fill their homes with pieces taken from a makeshift shop which she has stuffed to the gills with old sofas and ornamental lamps – donated cast-offs which are then upcycled to meet the tastes of whoever is on the show that week. "What exactly is wrong with the term 'nice boyfriend'?" Allsopp asks, glaring at her phone, adding "I never say 'chap'."

One sentence particularly riles her: "Look, this woman says, 'She is clearly writing from a position of immense privilege'. EXCUSE ME, this is my imaginary child, the child of two people who left school at 16 and 17 and have neither had anything from their parents – well I did get the deposit on my flat but it was a loan. [She bought her first home at 21.] And we've both worked really hard. Yes we've both been hugely lucky and we are hugely privileged but I think that somewhere people think I was born and somebody dumped a shedload of money on my head and I swanned off with it. But that isn't the case, it really isn't the case.

"So anyway," she says, scrolling down: "This woman goes on to say 'The reason I'm so angry with her is because I want to have children and I haven't yet'." She pauses before adding: "And that is a lot of the case. And I'm not saying that about all the people who have written about me in that way, but there are some people clearly for whom me saying that out loud, it has driven them insane because it's something women genuinely are worried about."

Allsopp lives with her property developer boyfriend, Ben Andersen, and their two children, Bay, seven, and Oscar, five, in a house in Holland Park, west London, which she describes as "ugly, very neat but not all matchy-matchy". According to her website, she was first approached by a Scottish production company several years ago "to take part in a screen test for a new property show... There I met Phil, we instantly hit it off". Since then, there has been a slew of home improvement shows and related books which have made her a reliable public voice rumoured to be an occasional advisor to the Government, and today she also owns her own production company.

The eldest of four children, Allsopp was raised mainly in the village of Inkpen in Wiltshire and attended 10 different schools including Bedales and St Clotilde's in Gloucestershire, describing her younger self as "pretty bloody hellish". Her father, Charles Allsopp, is a former Sotheby's chairman, former member of the House of Lords and the 6th Baron Hindlip. Her mother, a frame mounter-turned-interior decorator, was diagnosed with breast cancer when Kirstie was 15 and died earlier this year.

Understandably, her mother's passing is weighing on her mind: "The other thing people say to me is, 'Life is really long'. A great friend of mine's friend died aged 57 on Monday. My mum was 66 when died, she was younger than I am now when she got cancer," Allsopp says. "We may live longer but all of us don't live longer, and I'm starting to get into this thing where it's not just people's parents dying but it's siblings, people's older brothers and sisters. You get to a point early in your forties when you start going to more funerals than weddings." Her answer to why she waited until she was 35 to start a family of her own is simple: "I didn't meet anyone". As she tells it, that wasn't a choice: "Because we had this breast-cancer thing in our family, I knew we needed to have one sooner rather than later."

We meet for our interview at a photographic studio in north-west London, where Kirstie – who is also step-mother to Hal, 13 and Orion, 10 – has spent the morning being photographed for an issue of Heat magazine, in a Paul Smith dress ("It breaks my usual rule of flattering first, pretty second") and a pair of blue Zara heels, chosen to downsize her "enormous" size-eight feet. From the moment I walk through the door, she starts to talk. By the time we finish, 45 minutes over our allotted time-slot, she has barely paused for breath (once transcribed, her diatribe runs to 14 pages, about 23 per cent of which is swearing). She is a journalist's dream (and publicist's nightmare), refusing to stick to the script, incapable of filtering her thought-processes; after a question, she regularly drops her face into her hands, sighing as if in the early stages of labour, before stampeding off on an emotionally-charged tangent.

Earlier this month, she was on Question Time with food writer Jack Monroe and various MPs. What did she make of the politicians? "They were nice and friendly but really pretty pleased with themselves," she begins and then speaks again, more slowly, as if losing control of her facial movements. "And... oh God, I'll tell you, OK? What I think – and I'm not getting at him because he's the Labour MP at all, it's just because this is what happened – I was having my make-up done, Tristram Hunt came in, quite keen I thought to get his make-up done. I was like, 'I'm a girl, you're a boy' – and before anyone says 'Boys are entitled to look good'... Anyway, he mentioned a private girls' school that we both knew and he said 'Oh, you're probably a typical Downhouse girl' or something, and I thought, my God, you're the [shadow] Education Minister!"

While she says she is "frightened by what's happening with Ukip," she adds "I can see why". "People like the fact that [Nigel Farage] speaks his mind and they turn a blind eye to the fact that a lot of the people who are Ukip supporters and Ukip councillors are profoundly sexist and racist and homophobic. I see why they appeal because all the MPs [for the main parties] are so scared of getting it wrong."

She also denies claims that she has advised the Government on housing. "Let this be the final word on it," she says, conceding that she did go to John Prescott to lobby for the abolition of seller's packs, which was the first piece of legislation the coalition passed on taking office. At the time, Michael Gove was Housing Minister. What was he like? "Michael's very, very, very funny. I saw him give a wedding speech once at a close friend's wedding, it was the funniest speech I've ever heard, I thought I was going to puke..."

The Government, she says, never has and probably never will ask her advice on housing. But if they did, she would tell them this: "It's about small steps. Firstly, we have to stop thinking in a London-centric way, there is not a housing crisis in the rest of the country, there are issues but they're not the same." Making solicitors "sort themselves out" should be another priority to banish transactional difficulties. ("Although it's difficult, because nobody thinks they can do anything about it and governments are terrified to legislate against the lawyers.") "Then – and I know it's going to cost a fortune, I know it's dangerous, I know it's fiscally risky – but we have to get this slabbing out at £250,000: it should be stamp duty of 1 per cent up to £250,000, and 3 per cent on last amount." She also believes shop-keepers shouldn't be allowed to store things above their shops: "There must be priority for residential". She would like to see pod-housing on retail units, and more rural housing created: "There needs to be 10 more post-war-style box houses built at the edge of every village".

Finally, what is the answer for the lost souls of Generation Rent, stuck in a weird (and expensive) purgatory between a culture obsessed with property shows and period features, and an inaccessible housing market? The problem, she says, cupping her face in her hands and whispering "Here we go again..." is this: "I think that people aren't necessarily doing it [buying a place] soon enough. The average age of buying a first home is going up and up and up, and I don't think that's all to do with cost.

"Outside the M25 south-east bubble, cost is not so much of an issue and there are loads of places where there is a degree of affordability to a certain extent. When you look at the help-to-buy scheme and look at the figures on that, a high percentage was outside London and a high percentage was below £250,000 and you realise that it is possible and I think that is the problem that we live in a very London-centric universe."

We manage to stick to the subject of housing for about two minutes before recent events take over again. During these minutes it is as if there is something she wants to say, but daren't, so that her conversation digresses and falters. "There are a lot more people deciding to get a house together... There's definitely been a shift where instead of people saying 'Will you marry me?' they say 'Let's buy a home together', and maybe – maybe, I don't know – in saying 'Let's buy a home together' they haven't had that conversation about when they want children, maybe that's part of it."

"In the past, people got married younger and a man would assume that his wife wanted children, and those women who didn't had a miserable time and they were many women. But there's a great little thing called birth control and women in Tanzania don't get it." (Allsopp explains that she recently went to Tanzania for Comic Relief and visited Dar Es Salaam, visiting a sexual health clinic there.) "Your average Tanzanian man wants seven kids and your average Tanzanian woman wants three kids, and 50 per cent of Tanzanian women will have some exposure to violence every week.

"You know the whole thing in other places is completely different but obviously you see now we have..." Suddenly she pauses, in a moment of acute self-awareness, and throws her hands in the air. "See? Now, you see now I'm a WRECK!" She breathes and continues: "Obviously, we have domestic violence in the UK... Can you see? I'm caveating every f***ing word and swearing a LOT... but we do have access to birth control, we do get to choose when we don't have children but perhaps we shouldn't think that means we get to choose when we DO have children." Then, in a seamless loop back to her previous point, she says: "I've seen people on the show who say 'If we find the right house, I'll get pregnant, I'll have a baby, if we just find the right house'! No. Just buy any old house, get in and get knocked up." At that, she breaks into knowing laughter and then sighs. "So that's probably going to be the comment then... Here we go".

'Kirstie's Fill Your House For Free' is on Channel 4 in early July