Can peace survive such sabotage?

For the Irish peace process to be brought down by a newspaper leak would be a terrible thing - the triumph of spasm over seriousness. This morning we cannot know whether the ambush has succeeded. But we can ask why some Unionists are so panic-stricken, so frightened of politics as to try it. After all, Ulster has been promised that nothing would happen without the consent of the people of Northern Ireland, the parties, and the British Parliament - the democratic "triple lock''.

And yet yesterday, the Unionists were behaving as if the Times had uncovered a dark and sinister plot. Do they and their Tory diehard allies really think that, in the end, a Conservative government dependent on Unionist and Tory diehard support, would impose arrangements on Northern Ireland in the teeth of their anger and without a referendum? Are they stupid?

Many people will answer brusquely, yes. But the Unionist leaders are not stupid. They are genuinely frightened that they might lose their veto over political change. To understand why, and to understand the motivations behind yesterday's leak, we must pick open, barrel by barrel, Sir Patrick Mayhew's triple lock.

First, the question of popular consent, to be validated by a referendum. There is a yearning for peace in Northern Ireland which does not tire as the bloodless weeks succeed one another, but which actually grows stronger. From a diehard perspective, there is a serious danger that popular attitudes might soften. They might even find (their God forbid) that John Major's plain appeal, as made on television last night, rang louder bells in Belfast than the old-time religion.

Second, there is the matter of the British Parliament. For the Ulster Unionist, this is even less of a guarantee than the referendum. Asking the Commons may seem like a safe thing for them to do - but it might prove no safer than asking the people.

The danger John Major faced this week, and will face for as long as the process continues, is that rebellious Tory nationalists, Ulster Unionists and the Opposition combine against him. If the Government suffers a sudden death, this is how it will die.

The Prime Minister had clearly hoped to get the nine whipless rebels back into the parliamentary Conservative Party before he had to confront the Ulster Unionists with the so-called "framework document'' on Northern Ireland's political future. Why? Because he knows as well as anybody that there is a convergence of outlook between the rebels and the Unionists.

It is not simply that the leaked document suggested (unsurprisingly) that a North-South Irish authority would make policy for the whole of Ireland "in respect of the challenges and opportunities of the European Union'' - demonstrating, in the narrowed, glinting eyes of true British nationalists, that Brussels gold is to be used to achieve the break-up of the UK. It is also that the Tory anti-Europeans and the Ulster Unionists have always seen the world in similar terms; the same nationalist instincts that revolt at the idea of European Union tend also to revolt at the notion of weakening the Union between Britain and Northern Ireland.

A politician with these instincts will feel some personal contempt for John Major's lack of ideology and a deep, ingrained suspicion of Whitehall. These feelings will be the same whether the politician comes from Belfast or the English provinces; and in both cases they will have received their intellectual sustenance from one particular Homburg-hatted gentleman.

For the long shadow of Enoch Powell falls across the Commons still - he is both the precursor of the Tory Euro-rebels and the comfortless conscience of Ulster Unionism. It was in part to answer the silent presence of Powellism in his party that the PrimeMinister was obliged to bring Lord Cranbourne to his late-night meeting of Tory MPs on Tuesday. "No one could be more Orange than I,'' said the Leader of the Lords. In private, Major needs to wave the Orange card: nothing could be more damaging to his government than a united front from the Powellites of England and Ulster.

But the great problem for Unionists who hope to use the Commons to block any move towards joint Irish institutions is that Labour and the Liberal Democrats are solidly with the Government. As with Europe, there is a large Commons majority for the peace process which crosses party lines.

Naturally it would be a great temptation for Labour to combine with right-wingers to bring down a government as unpopular as this. But for Opposition leaders to join with diehards to wreck the Irish peace process would be an act of horrific political cynicism with unpredictable electoral consequences: and for the Tory diehards to allow this to happen would, of course, be politically suicidal for them, too. These things happen in the headquarters of Swiss cults, not in the Commons.

In the end, then, the Ulster Unionists' instinct about Parliament, which is that it cannot be relied upon to defend their political viewpoint, is right. At Westminster they are a small, aloof and mistrusted minority.

So two of Sir Patrick's locks are not nearly as secure as Ulster Unionists would like. That leaves the third and strongest, the consent of the Northern Irish parties themselves. But this " lock'' cannot, in practice, be isolated from the other parts of the process.

The formal and guaranteed role for the parties might be overtaken and encroached upon by popular momentum for a deal. In theory, the parties could stand for ever, simply saying no. But in reality, if there was a proposal which was being supported by large opinion-polling figures in the North, and by most MPs in London and Dublin, a proposal which offered continued peace after however many murderless months had by then passed - for how long would their authority as nay-sayers survive?

Hence, despite the appearance of a triple guarantee, the expressions of genuine worry and anger among the political leaders of Unionism. And hence, too, of course, the leak.

Sir Patrick said that "extremely malign forces'' were at work, and he was right. Leaks are the weapon of losers. This one appears to be a cold attempt to sabotage a delicate and uncompleted process of negotiation. The Times colluded in the attempt, rather than merely acting as the conduit of information - for instance, by informing its readers that the proposed cross-border institution "will be seen by many on both sides as the engine for the reunification of Ireland''.

The Unionists' core problem, which concerns the autonomy, or lack of it, that the new Northern Irish assembly would have over cross-border institutions, is not properly answered by those leaked paragraphs. But the leak was not an attempt at negotiation through the public prints; it was an assault on the process itself.

The leak, and the way it was presented, gave extremists and careerists an opportunity to try to destroy in a sudden political storm something they feared might survive a more thoughtful reception. Well ... I hope the "spin" on the leak came about through

thoughtlessness rather than malignity. I hope those responsible slept badly last night. And I hope it doesn't matter.