Is it too late to save Eric Pickles from himself? By rights, the popular architect of the Tory victory in Crewe and Nantwich should not have much longer to wait before he becomes chairman of his party, replacing Caroline Spelman (victim of unfortunate mix-up involving public money and her children's nanny). When they were invited to pick a fantasy chairman to preside over the party conference, visitors to the Conservative Home website recently offered Pickles their overwhelming support, with 52 per cent of the vote.

What possessed them? Although the poll was held a few weeks before shadow health spokesman Andrew Lansley declared that fat people have no excuses for their behaviour, that does not exonerate the Pickleites, who must already have been well aware of David Cameron's engagement with fat politics, from his concerns about chocolate oranges and undisguised disgust for those who eat too many of them.

'We talk too much about people being "at risk of obesity" instead of talking about people who eat too much and take too little exercise,' he said, in his celebrated attack on moral failure in the broken (except for Boris Johnson's bit) society.

So the time has long passed since Pickles could claim that he is just big-boned. Did his supporters not consider, in their enthusiasm, what message the choice of an obese-looking party chairman would send out to fat people who must learn, as Lansley re-emphasised, last week, that 'the buck stops with them. They can't shuffle off the responsibility'?

Although his party has not, as yet, completed the downloadable table which will tell us, at a glance, the body mass index of every sitting Tory MP, it must be clear, even to non-dieticians, that Pickles's figure betrays him as exactly the type of person whose slack, self-deluding, ultimately irresponsible behaviour must cease, before the country is flattened by their collective weight.

'Changing our culture is not easy or quick,' Cameron warned. 'You cannot do it top-down. But you can give a lead.' The wonder is that Pickles has not followed it already. But conference is still four weeks away. That leaves ample time, on the No Excuses diet, for him to rediscover his bikini body.

Week One. Goal: re-education. This is when Pickles should completely undress and take a good, hard look at himself in the mirror. How did he get here? It's not good enough to blame lack of tone on the influence of obese friends and colleagues, such as Nicholas Soames or Lord Strathclyde. 'Peer pressure and social norms are powerful influences on behaviour,' says top dietician Lansley, 'and they are classic excuses.'

Week Two. Goal: healthy eating. And where better to find nutritious inspiration than in the fantastic Unilever range of products? In his No Excuses speech, Lansley announced that Dave Lewis, chairman of Unilever UK, is to chair the Tories' new 'Responsibility Deal' on public health.

For breakfast, Dave, who graduated in something or other from Trent Polytechnic, recommends a yummy Magnum, as advertised by slender Hollywood actress Eva Longoria. 'Did you know,' he says, 'that, eaten sensibly, ice cream can be part of a healthy balanced diet?' Yet another reason, as the food industry has been arguing, to abandon the stigmatising traffic light labelling system. Isn't it much fairer on ice cream to stigmatise people instead?

Lunch: Eric should choose from Unilever's range of tasty Pot Noodles; just one will supply around 25 per cent of his daily recommended sodium allowance! His light evening meal could be anything from the Unilever list, from a delicious bowlful of Hellman's mayonnaise to a comforting cup of Bovril (assuming the source of the recent salmonella outbreak has now been identified).

Week Three. Goal: enjoy exercise! Eric will find out how fun and exciting this can be if he tunes into CBeebies' LazyTown, featuring the Tories' favourite keep-fit instructor, Sportacus. This character is mentioned so often in connection with Tory health plans that you might easily get the impression that Sportacus, Cameron and Lansley are collaborators. But that would mean helping fat people, and as Sportacus creator Magnus Scheving says: 'LazyTown does not align itself with political parties.'

Week Four. Goal: developing self-esteem. By now, Eric will be admiring his new curves and wondering how he could ever have fallen for the line, promulgated by the authors of last year's Foresight survey, that the UK's adiposity explosion is related to conditions in the 'obesogenic society'.

A top priority in Lansley's No Excuses programme is to keep the public away from that kind of damaging misinformation. 'Tell people that biology and the environment cause obesity,' he warns, 'and they are offered the one thing we have to avoid: an excuse.' So even if Pickles already knows about the dire consequences of dietary abundance, human biology and a sedentary lifestyle, please don't mention this to any other Tory MPs who might use it as an excuse not to shed pounds of unattractive flab.

It's hard to judge, at this early stage, how the Cameron anti-fat campaign compares, in hostage-to-fortune terms, with John Major's back to basics. Even supposing there are fewer extremely fat Tories than priapic and/or corrupt ones, there could still be morale implications for his plumper backbenchers, struggling for survival in the party of the thin. How long before some sobbing junior minister describes the horror of the constant weighing and hurtful criticism from party whips? At least fashion's size zeros get to be supermodels.

Far riskier, however, is the possible impact of insulting one quarter - the obese section - of the adult population. Last week's map of obesity 'hot spots' suggests that not all of these potentially offended people are the deprived inhabitants of guaranteed Labour seats (supposing such places still exist). There are quite a few inexcusably obese people, it turns out, in Tory seats like Kensington and Chelsea. And, as much as the careers of Gillian McKeith and Anne Diamond reveal a surprising tolerance, on the public's part, for dietary advisers who may be unqualified, unhinged or five stone overweight, it seems to draw the line at abuse.

Jamie Oliver is unlikely, ever, to regain the popularity he enjoyed before he put on a fat suit and advertised his moral superiority over the 'fucking arseholes' and 'tossers' who feed their children badly. And Oliver, at least, offered recipes with this analysis. The Tories' intentionally arm's-length initiatives amount to Cameron's rebukes, Lansley's 'no excuses', the promotion of Unilever's Mr Pot Noodle, and an end to traffic light food labelling.

Of course, while obese people remain a minority, their demonisation might turn out to be a terrific vote winner. Easy to spot and fun to tease, they are also the perfect guinea pigs for Cameron's new, bottom-up approach to governance. It might just work. And if it doesn't, there's a perfectly good excuse: it's the fat people's fault, with knobs on. That's something to think about, Eric Pickles.