Editor-At-Large: M&S has its USP – but it's not a value pack of underpants

There's a large piece of ham sitting in my fridge, reminding me of the ghost of Christmas past, and I know that plenty of you will have similar food gluts nearing their sell-by dates.

That's the big dilemma in January, isn't it? As the first credit card bills start to arrive listing those fatal impulse purchases you really seemed to need in December, the temptation to economise and carry on eating the unopened boxes of mince pies you over-ordered a month ago is immense.

I realise that this is, of course, a middle-class way of looking at things. You have to be middle class to shop in bulk, order in advance, and have several credit cards to spread out your debt.

The chief executive of Marks & Spencer, Sir Stuart Rose, made an important pronouncement last week when he unveiled the first fall in the company's sales for two and a half years. He noted: "I have never seen such a polarised UK economy... the rich are so very, very rich... but the poor are getting poorer."

The 2.2 per cent overall sales slump at Marks & Spencer was in spite of its lavish Christmas advertising featuring Antonio Banderas. It led to the price of its shares dropping by 20 per cent at one point in the day results were announced. Marks & Spencer retained its share of the market, but only by discounting prices.

As the UK's biggest clothing retailer, Marks & Spencer is a good indicator of what is happening elsewhere. The British Retail Consortium says sales in December grew at the slowest pace for two years. With the outlook continuing to be even bleaker, the big question will be whether Marks & Spencer can continue to pour money into updating and revamping its stores.

Marks & Spencer cannot afford to position itself as a swanky store patronised by the middle classes – the last time it did this, over a decade ago, shoppers deserted it in droves. So Rose has no choice but to confront the giant of Tesco head on. He is said to be preparing to roll out online food delivery – and has poached a top man from Waitrose in preparation to expand the range of food and stock more of the basics that you need to make a meal.

Both of these propositions make me a bit nervous. I, like millions of others, would say that John Lewis and Marks & Spencer are simply the most pleasant places to shop, for all sorts of reasons, starting with staff, then their returns policies, size of premises, and quality.

When I order online it nearly always ends with a slight disaster. At Christmas I ordered wine from Tesco. About 20 bottles arrived, all wrapped in individual plastic bags. There were loads of weird substitutions like San Pellegrino for tonic water, two completely different drinks. An expensive ham I ordered from Suffolk over the internet arrived as a different cure from the one specified, with no covering letter of apology. Both experiences are good reasons for trying to shop in person whenever possible. I would be disappointed if Marks & Spencer stopped upgrading its shops.

Next, the ludicrous idea of Marks & Spencer stocking things such as dried beans and pulses – please show me a working woman who's got the bloody time to soak a haricot bean. Why fill up shelf space stocking sugar and flour? Who has got the strength to lug this lot home on public transport? What we want is cleverly thought out stuff that we can pass off as our cooking, giving us time to do other things.

But Rose's observation about the gap between the rich and poor means that he will struggle to appeal to those at the bottom end of the income scale – and filling his shop with packets of 10 underpants or 20 socks in value packs will just look nasty and scare away the middle-class shoppers.

The high street is polarising – take Oxford Street in London, where luggage shops and discount retailers sit alongside Selfridges, where the average handbag sold is more than £600.

It might be called "our M&S", but the price of entry is too high for an increasing number of shoppers. On the other hand, it would be a mistake to drop the price of its food to take on Tesco and Sainsbury's with their basic ranges. Marks & Spencer has to hold its nerve and stand for quality. That's its unique selling point.

A likeable 'Big Brother'? Strange, but true

I'm embarrassed I watched Jade Goody and Shilpa Shetty on 'Big Brother', fascinated by the car-crash television unfolding in front of me. So when the programme called me last month and asked me if I was interested in a new concept for the current series, I was sceptical to say the least.

But this new revamped 'Big Brother' (on E4) is a welcome breath of fresh air. Not only are all the young people intelligent and articulate, they are also providing great role models for their peers. I was allowed to hijack the programme last Friday, following the efforts of Russell Brand and Matt Lucas on previous days. Huge fun as the inmates had to make three different TV programmes aimed at their age group – a debate, a spot of reality TV and a chat show.

Best laugh was when Anthony, a young boxer, cooked supper, aided by Tom, a young politician. Gordon Ramsay had better watch out – this kid could really get young girls interested in catering. He's charming, likeable and a totally self-effacing heart-throb. A potential winner.

A dollop of self-belief does more good than a grapefruit

Everywhere you look in January advice is being beamed at you. At the newsagents little booklets full of army exercises drop out of the morning papers.

I am so sick of being told to spend loads of money to turn myself into a better groomed, more svelte, well-toned and mentally alert human being that I've turned my discontent into an anti-self-help book called Life's Too F***ing Short (Quadrille, £12.99). OK, you could accuse me of writing more advice, but this book is a rant directed at the expensive range of lifestyle gurus and helpers who have grown up over the past few years.

I don't know about you, but I read some newspaper columnists at the weekend and just end up feeling inadequate. The colour magazines are full of people cooking complicated dishes, repainting their attics, recycling everything in the larder, and spending an hour a day doing press-ups or visiting a yoga class.

Then there are the perverted female journalists who write about the beauty industry. They rarely bother to tell you that cheap cream is as good as expensive stuff and use verbiage that's wilfully confusing and sometimes just plain naughty – generally implying that the more you spend, the more chance you have of looking a decade younger. We all know that eight hours' sleep, no class A drugs and no booze get the same results. And show me a fashion editor who will prefer a bag that costs under £50. Fat chance.

I'm a great believer in sorting things out for yourself. Start each day, not with a grapefruit, but by telling yourself you are great. No one else is going to, believe me.