Richard Ingrams’s Week: I decide who to vote for – and then something puts me off

As a floating voter, I have traditionally based my decision on whom to vote for on purely negative and, it has to be said, extremely trivial issues.

Thus if ever in the past I was tempted to vote Conservative, at the last minute I would be deterred by the quite obviously Tory ladies who used to sit outside the village polling booth monitoring the voters as they came and went.

The same kind of principles operate on a national scale. I cannot claim to have examined the Tory party's policy in any great detail. But it is the sight of Sir Michael Caine, the very rich and pretty boring actor, sitting alongside David Cameron advocating the need for Britain's disillusioned few to volunteer for two months' community service – the sort of thing we are accustomed to hear from Prince Charles – that has done more than anything to dampen down any possible enthusiasm for the Conservative cause.

Do those Tory spin doctors think that Sir Michael Caine will go down well in the marginal seats? Or what about all those prominent businessmen who this week signed a letter deploring Gordon Brown's intention to raise the rates of National Insurance?

This was interpreted as a major blow for the Labour Party. But I wonder. Big businessmen must nowadays score very highly in any poll for the most unpopular role models in the community. All that most people know about them is that they pay themselves vast salaries and look forward to equally vast pensions when they retire. And as with Sir Michael Caine, would not the thought of Sir Richard Branson nailing his colours to the Cameron mast be enough to cause the swingometer to dip sharply towards the red section?

Why is Cameron aping Blair?

Have you noticed how David Cameron makes a point of appearing in public in his shirtsleeves? Even on a cold day you may see a group of Tory would-be ministers seated round a table in their dark suits with Dave at the head sporting a shiny white shirt, open-necked for the most part.

This is the most conspicuous way in which Cameron imitates Tony Blair, who liked to demonstrate not just his informality but his physical fitness (in contrast to his colleagues) by appearing jacketless regardless of the low temperature.

This ploy worked well until one day a sharp-eyed press photographer noticed a fragment of vest peeping out over the prime minister's wrist. Does Cameron, I wonder, resort to the same underhand kind of trick?

A more pertinent question perhaps is why Cameron is so determined to model himself on a politician who in the eyes of the general public is now a disgraced and discredited figure.

Nick Clegg, the Lib Dem leader, is the same – a smiling, boyish figure chosen by his colleagues for his superficial resemblance to Blair. Yet Clegg has now been reduced to appearing in public with the more capable – albeit old and bald – Dr Vince Cable at his side.

Will Cameron in the end be forced to do the same and persuade Ken Clarke to make up a similar kind of double act?

There's an art to knowing when to quit

Not for the first time I write in praise of the Labour MP Chris Mullin, who will not be standing again at the election. Mr Mullin, whose recently published diaries are well worth a read, has no special plans for the future. The decision to quit is what he calls a "high-risk strategy", adding that "there is not a huge demand for balding, white former politicians of a certain age".

Mullin is not alone. My friend Martin Salter, the MP for Reading West, is also taking a leap into the dark – 6 May will be the first day of the rest of Martin's life.

If only more people felt the same way, and not only politicians. I was full of praise recently for Terry Wogan when he gave up his job on Radio 2, deciding that it was better to quit before he was ordered off the air.

This week it was reported that Jeremy Paxman, pictured, had fluffed an interview with a group of MPs, misreading the autocue and making a bit of a fool of himself. The reason, I suspect, is that Paxman is just bored – not surprising in view of his many long years talking to politicians late at night. He must be equally bored with sitting in Manchester reading out futile questions to panels of university students.

Why not follow the brave example of Mullin and Wogan and cast off into the unknown. "Death closes all," as Tennyson's Ulysses tells us, setting out on his final voyage, "but something ere the end, some work of noble note may yet be done."