Alan in Arthur's seat

If Peter Mandelson, Philip Gould, all the Saatchi brothers and the entire US advertising industry had been asked jointly to dream up the perfect launch for Labour's campaign to fight the next election, they might just have have come up with last week's threatened defection of Arthur Scargill (from New Labour to socialist pastures unnamed) and yesterday's actual move of Alan Howarth MP (Conservative to Labour). The old class warrior of another era trudges off trailing his megaphone; a one-nation Tory arrives, borne on a warm wind - fresh with the scent of rose petals - to reassure the voters. They'll be whooping it up in Islington tonight.

For all the indignation - much of it genuine - expressed by his former colleagues at Mr Howarth's decision, the charges of treachery or of being a rat deserting a sinking ship will not wash. A cursory glance at the things that Mr Howarth has been saying and doing over the past couple of years shows that his defection is completely logical. Over the Disability Discrimination Bill, Mr Howarth showed courage and tenacity in opposing the Government's disgraceful decision to permit discrimination against the disabled in more than 90 per cent of British companies. He voted against the Jobseeker's Bill, argued for more money for education and has spoken out against xenophobia in the party. In a political world less dominated by whips and nervous careerism, such moves as Mr Howarth's would be more common and less surprising. More MPs from all parties ought to do it.

The worries about him begin when his letter of resignation is subjected to scrutiny. What exactly does Mr Howarth wish to achieve inside the Labour Party? According to the letter, he has argued for the past three years that the Tories "should return to the 'one nation' tradition [and] heal the divisions in our society". Now, he says, he sees Labour as the one- nation party.

This is not encouraging. The idea of one nation is one of the most sterile cliches of modern British political life. It is either used (as by John Major in his "a nation at ease with itself" speech) as a cover for inactivity; an excuse for dumping unpopular stances - or (as by Margaret Thatcher in her gut-wrenching "Francis of Assisi" quote in 1979), as a meaningless piety. All too often it denotes a return to the Butskellite post-war consensus, where tough decisions are dodged in the hope of avoiding upsetting people - with the eventual result that public expenditure occupies an ever larger share of the nation's wealth. It becomes a cover for risk aversion and an unwillingness to debate or take radical steps.

If this cosiness is what Mr Howarth yearns for, then Labour has too many of his kind already cluttering up its benches, ready to oppose any uncomfortable radicalism. There are, however, two straws in the wind that give rise to optimism. In an article for this newspaper earlier in the summer Mr Howarth reminded us all that "gouverner c'est choisir" - government is about taking tough decisions. Second, earlier this year Mr Howarth courteously but firmly upbraided the Shadow Health Secretary, Margaret Beckett, for failing to speak the language of priorities.

These examples are not conclusive. But they give us a little hope that Mr Howarth could be as awkward and rumbustious a Labour MP as he has been a Tory one. And that is what the country needs.