One of the many disturbing questions facing Mr Major after the defection of a second Tory backbencher - Miss Emma Nicholson, who joined the Liberal Democrats last week - is how far she reflects the depth of ideological difference among Conservative MPs and how many more are prepared to follow her out of the party. In both her case and that of Mr Alan Howarth, who defected to become a Labour MP last October, total secrecy was maintained until the announcement was made with consummate stage management designed to inflict the greatest possible embarrassment on the Tories.
If there is a trend, it could have long term implications for British Conservatism as the post Thatcherite struggle for ascendancy works its way through. The Euro sceptic revolt revealed a significant number of MPs who were prepared to stop at nothing to secure their ends. Mr Major's willingness to compromise with them, and the growing confidence of some strong opponents of the European Union, like the Minister of Defence, Mr Portillo, have changed the complexion of the government.
There must be considerable doubt about whether, after a general election in which its hopes are likely to be pinned to the material appeal of lower taxes rather than political principles, the Tory party can reassemble itself in any recognisable form as a credible political force. With Mr Blair's New Labour becoming accepted as an effective representative of the middle ground, the traditional party lines are in the process of being redrawn.
A more immediate question is the impact on the Northern political process and on Anglo Irish relations generally. A government in London staggering from crisis to crisis and dependent for its survival on the support of the Ulster Unionists is not the best formula for successful negotiations. There are a number of reasons why this bleak scenario may not be inevitable (not least, as our London editor Frank Millar reports, Mr Major's attachment to the peace process). But no reckoning of the chances of progress this year can leave out of account the extreme fragility of his government, and the possibility of its abrupt collapse.
That would not be a calamity because the degree of bipartisanship in Britain in regard to Northern policy is probably as high as it has been for many years. A change of government in London would not mean an abrupt change of course. But Mr Blair with a comfortable majority in the House of Commons would have certain advantages that Mr Major, torn between the atavism of the right wing Tories and the commitments of the Downing Street Declaration, does not have and could introduce a much needed flexibility to British tactics. Any temptation that the UUP leader, Mr David Trimble, may have to prolong the present state of affairs must be tempered by the risk this would entail of closing off future options.
Everything will depend on whether there is a peace process to revive. The statement by Mr Pat Doherty, after seeing government officials in Dublin yesterday, that Sinn Fein was exerting its influence to bring the current IRA campaign of murder to an end, is good news if it succeeds. And it must succeed if the current sense of erosion and uncertainty is to be reversed.