'Wills and Kate? Not my cup of tea': How republicans are plotting a right anti-royal knees-up

Graham Smith and a group of friends are busy putting the finishing touches to their royal wedding weekend plans. There'll be a street party, a magician and face-painting for the kids. Then, in the evening, they'll move to a venue near London Bridge station, where a line-up of bands and DJs will carry the party on into the night.

But unlike all the other street parties happening on Friday, there will be no waving of flags or unfurling of royal bunting – for Smith and his cohorts are members of Republic, a campaign group calling for the end of the monarchy. And the event they are planning is an alternative party called Not the Royal Wedding.

On the day I meet Smith and his fellow activists, tensions are running high, because Republic have just heard that they have been banned by Camden Council from using Earlham Street, just off Covent Garden – the site they had been promised for their party – due to fears that the event could be hijacked by anarchists. Looking around the table, there's a banker, a charity worker and an academic among their numbers – ordinary thirtysomethings who have come from their ordinary office jobs to discuss where to park the ice-cream van and whether or not to have a cupcake stall. It's the most unlikely bunch of anarchists I've ever seen. "Camden have reneged on a previous agreement," says Smith. "It's a disgraceful attack on the rights of republicans to make their views heard. But we're not giving up. We're going ahead with this somehow."

The royal wedding has been a gift to Republic. Perhaps it's the sight of Kate and William grinning at us from all that commemorative crockery, or the fear of having to live through something akin to the Charles and Di years again, or possibly these straitened times, but the royal wedding appears to have people signing up with Republic in their droves. "In November, when the royal engagement was announced, we almost doubled in size from around 8,000 members to 14,000," says Smith. "It's been a sudden, substantial shift."

Since January they have taken on two part-time members of staff to help Smith, who works on the campaign full-time, cope with the increased workload. At the time of writing, their Facebook page stood at 7,462 members.

It certainly hasn't always been so popular. When Republic started in 1983, it was made up of a few old lefties and functioned more as a political club. The royal scandals k of the 1980s and 1990s galvanised it into a pressure group but even so, seven years ago, it still had only around 300 members. It's been under the leadership of Smith, who has been at the helm since 2005, that it has been transformed into a modern-day protest group, full of young bloods eager to get their cause on the agenda.

"We're a lot more diverse in terms of our demographic," says Smith. "And now we're also a lot younger – everyone on the board is under 40 and some are in their twenties. Plus, we are a broad church, we don't exclude people – we have Tories, Liberals, Labour, Greens, and Scottish and Welsh nationalists, all under one roof."

They have a large number of celebrities on their side, too. Richard Dawkins is a new recruit, "although he's too busy fighting religion to get really involved". There are others you'd expect – Jo Brand, Mike Leigh, Ken Loach, Sue Townsend; and a few more surprising names – the former football star Stan Collymore, for example, "recruited when I went on TalkSport", says Smith, as well as 1980s pop star Captain Sensible. They've also got an MP, the Liberal Democrat Norman Baker, on their side.

Smith, who previously worked in IT, describes himself as a "constitutional anorak", and his motives essentially boil down to a point of democracy: he doesn't think our head of state should be unelected and unaccountable. Some fellow members object on the grounds of hereditary principle, while others think the monarchy is a waste of money and still more simply dislike our own particular brand – the Windsors themselves – whom they consider offensive, racist, bumbling or plain embarrassing.

"It's a paradox, because while the Queen is enormously powerful, she is also powerless, as all the power is in the hands of the prime minster," says Smith. "One argument in favour of the monarchy is that it gives us a neutral, impartial head of state, but actually she's not impartial, she's just a puppet of the PM. She is pointless and does nothing of worth other than go round opening things, cutting ribbons and making speeches that are completely unmemorable."

But aren't the royals brilliant for highlighting our rich historical traditions and bringing in tourists? "Would tourism suffer if you got rid of the monarchy?" asks Smith rhetorically. "There's not a shred of evidence that it would. And even if it did, this is about democracy. The British shouldn't be abandoning our rights for the sake of selling a few T-shirts." He notes with barely concealed glee how only one royal residence – Windsor Castle – features in the top 20 most-visited UK tourist attractions (number 17), beaten comfortably by that other well-known Windsor destination, Legoland (in seventh place).

It's worth considering too, the dubious behaviour of various members of the royal family. There's Prince Andrew, our trade ambassador, and his recent choice of associates, for one. There's Fergie, who was caught trying to flog introductions to her former husband. Similarly, Sophie, Countess of Wessex, who was exposed by the News of the World intimating to a potential PR client that her royal status could enhance their business. And that's not to mention the innumerable shameful gaffes of the Duke of Edinburgh.

But there are no cries of "off with her head" at this republican meeting. Rather, there is a quiet, confident belief that the end of the monarchy is nigh. They are working towards a referendum by 2025 and most of the members at today's meeting believe a republic is something that can be achieved in their lifetime. Already, despite the best intentions of the council, they have a potential new site, Red Lion Square in nearby Holborn, lined up for their party.

"There's a Gandhi quote that goes something along the lines of: 'First they ignore you, then they laugh at you, then they fight you, and then you win,'" says Smith. "Well, we're going through the laughing/fighting stage at the moment."

They are also reaching out to republicans across Europe. Last year a Republic delegation went to Stockholm to witness the marriage of Crown Princess Victoria to "some commoner – her gym instructor, I think", says Smith. There they met up with republicans from seven countries across the continent and formed the Alliance of European Republican Movements. This European contingent is due in London over the royal wedding weekend to make their presence felt and the group plans to meet annually.

For now, Smith believes there is an awful lot more than meets the eye riding on this week's royal wedding for the monarchy. "It's an institution that survives on births, deaths and marriages," he says. "The events of the 1980s and 1990s did them a lot of damage – a lot of people started to see them as a failure. They have put a lot of store in this marriage. It is their last chance to recapture that fairytale. I think if it ends in divorce, it will be catastrophic."

For more information on Republic and the Not the Royal Wedding street party, go to republic.org.uk

Jen Gingell, 31

Works in finance

"I think certain people would like to write us off as a group of trouble-makers, which I find very upsetting: I would be a terrible anarchist. I just think that fundamentally the monarchy is undemocratic and that Britain deserves a lot better.

"Hereditary public office creates a lack of accountability, elitism and a concentration of power. I think it creates a distrust which you see very clearly in the public's attitude to politicians at the moment.

"We deserve a moral and transparent democracy, rather than the half democracy we have at the moment. I want the public face of Britain to be aspirational and inspirational rather than having the Windsors portraying us as elitist, out-of-touch and bumbling."

Lexx Lewis, 24

Works for the YMCA

"I joined Republic in December. It was down to something David Cameron said about the royal wedding having an unlimited budget [sic: when asked whether it would be a budget wedding given the Government's austerity measures, he said: 'No, it will be a royal wedding that the whole country can celebrate']. Both my parents have been told they are going to lose their jobs in this recession. My mum works for the Trades Union Congress and my dad for the NHS. They have both always been fairly political and instilled in me a strong working-class ethic.

"I also recently found out I was also going to be losing my job. My last working day was meant to be on 29 April, so the wedding is depriving me of my final day at work.

"I'd like to see an end to the royals in a peaceful way. I don't want any chopping off of heads. If they bowed out gracefully and we moved on, that would be just fine."

Emily Robinson, 30

Political historian

"I was only a baby when Charles and Diana got married, but I do remember getting a day off school for Andrew and Fergie's wedding and wondering what on earth it was for.

"I've always instinctively felt that the hereditary principle is indefensible. My parents are not particularly political, but now I think that my mum has been a bit of a closet republican all the way along. My dad is more bemused. We often hear complaints that we have a very powerful executive prime minister, and that is tied to the slightly murky fudge at the top of the system. I think a lot of people assume that the Queen has the legitimacy to exercise some sort of checks and balance over the PM, but she doesn't."

James Gray, 30

Freelance campaigner and writer

"I've always had a strong sense that all this bowing and scraping in front of the royals is absurd. It's ridiculous that our most eminent scientists, for example, would have to address someone like Edward Windsor as 'Your highness'.

"Of all the royal families in Europe, we have been landed with a particularly bad one. You do have to ask yourself what is it that they actually do? We've got Charles, who gets sucked into all kinds of odd causes and who is an extremely self-pitying, tragic character. We've got Andrew, who appears to me to be just out to feather his own bed. We've got a Queen who has never cracked a smile or made an inspiring speech in her life; and the Duke of Edinburgh, who is just embarrassing. It's a really odd assortment of characters and I think the very idea of monarchy has an effect on the incumbents that turns them slightly odd."