LEADING ARTICLE : Can Hague stop the rot of party dissent?

Last year, Hugh Dykes was a "lifelong Tory", as he denied speculation that he was about to follow Alan Howarth, Emma Nicholson and Peter Thurnham by defecting from the sinking ship. Today, his Tory life has ended and his Liberal Democrat one has begun. The Conservative Party will dismiss him as a known dissident and an ex-MP.

There is nothing so ex as an ex-MP, but Mr Dykes matters - possibly more than he can imagine. He matters partly because of the breathtaking irrelevance of the parliamentary Tory party, hidden in dusty corners of Westminster while Tony Blair's majority of 179 carries all before it. The importance of Tory politicians depends - for the moment - on what they have to say, rather than whether or not they sit on those green benches in SW1.

And Mr Dykes not only has important things to say, but says them on behalf of a large number of people who are still members of the Tory party. As he explains on the opposite page, he joined a Tory party that believed in constructive engagement with Europe. Now the party is in the grip of an "insulting, isolationist anti-Europeanism". He was an extreme, rebellious pro-European, but he was not a lone maverick. There are many who share his views on Europe at all levels of his former party, including its rump of MPs, and including former Chancellor Kenneth Clarke.

What is interesting, however, is that Mr Dykes should have chosen to seek political asylum in Paddy Ashdown's party rather than in Mr Blair's. Whatever the disorienting effects of Blairism, and however much Mr Blair and Mr Dykes both talk of "One Nation", tribal feelings still run deep enough to keep them apart. Mr Dykes mentions only one policy which led him to prefer the Liberal Democrats to Labour: the pledge to raise taxes to pay for better schools and hospitals. Clearly, this makes sense to a local politician who fought bitterly against the closure of Edgware General Hospital. But it is striking that this is the only significant policy difference between the two parties.

So is the role of the Liberal Democrats now simply to act as a reception centre for defecting Tories who cannot quite bring themselves to go the whole hog? To pose the question is to begin to sketch out the wider significance of Mr Dykes's defection.

This week, the Liberal Democrats get their feet under, well, not the Cabinet table, but that of a Cabinet committee, and one chaired by the Prime Minister. This event will send further shocks through the post-earthquake landscape of British politics. It sends an important signal that Mr Blair is serious about the creative destruction of party political tribalism.

Nor is it a mere public relations sop: the committee will have real influence over vital questions for the future of British democracy. Most strikingly, the possibility of changing the electoral system for the House of Commons is wide open, with Mr Blair's own position evidently changeable.

This is not how most people thought of the "realignment of British politics" during the Tory years: everyone assumed that, if a proportional electoral system came, it would come as the price of Liberal Democrat support for a Labour government in a hung parliament. But Mr Blair has bigger ideas, in which electoral reform is secondary to a much wider realignment upon which he can build a lasting, progressive government.

Mr Dykes's decision suggests that the ties of party loyalty are continuing to break, and that the process of realignment has barely started yet. It suggests that the Tories, far from uniting under a new young leader, remain in a fissiparous state. It suggests that Europe remains a divisive issue. And it will do nothing to calm the first mutterings against William Hague's leadership, as the opinion polls repeatedly return their cruel verdict. When the Tory organisation in this country finally levels out of its tailspin and Sir Archie Norman applies the management techniques of Asda superstores to turn it into a modern, membership-based national party, whatever is left will be much smaller, ideologically, financially and in terms of membership numbers, than the dominant political force it once was.

In other words, the field is clear for Mr Blair: he is poised to achieve an ascendancy over our national life for which there are few precedents. It is quite different from Margaret Thatcher's strident pre-eminence because it is based on co-opting threats rather than fighting them. Mr Blair is more like the Prime Minister of a Government of National Unity. Always somewhat detached from his own party, he now appears to hover above all parties, capable of drawing from the best of each of them, as well as calling upon the talents of business leaders, trade unionists and showbiz stars. This is not coalition politics, or consensus politics. The right phrase is "coalescent politics", and Mr Ashdown seems to understand it well.

For some in Mr Blair's own party, it is all too much. But the real warning bells should be ringing in Conservative Central Office. This morning, Mr Hague and his spokespeople will condemn Mr Dykes as a petulant attention- seeker. They have to. It is part of the rules of the game. But let us hope that, in private, they are giving serious thought to how broad or how narrow the Tory party is going to be. They are in danger of being corralled into an anti-European ghetto, cut off from the political mainstream. Monetary union is, as we report today, rolling onwards, and permanent abstention is not a sustainable policy. Mr Hague must recognise that a Conservative party that cannot attract to its ranks people like Hugh Dykes will be marginalised for many, many years to come.