Let down that angered loyal bone cruncher

David Davis always seemed loyal to the point of brutalism. One reason why reports of his resignation threat have caused such shock waves in the Tory party is that since John Major took office in 1990 Mr Davis has carefully cultivated a reputation as the Government's bovver boy, the party's unflinching bone cruncher.

As the European whip during the Maastricht Bill's long hot summer in 1994, Mr Davis played a key role in finally delivering the vote for the Prime Minister. He was the Euro-sceptics' equivalent of his one-time chum, colleague and mentor, Tristan Garel-Jones. They did not agree in their view of Europe; but it seemed that, as highly intelligent and articulate politicians with a thuggish edge, they were as one in never letting their views get in the way of the job of propping up the administration. He was a tireless lieutenant of Mr Major's in the 1990 leadership contest, and even more assiduous in the one last year.

Mr Davis has denied the resignation threat more than once since it was first reported last month, and he continued to do so yesterday. But with neither Mr Davis nor Downing Street explicitly denying that he wrote a letter to Mr Major, it looks as though he was indeed making some kind of trouble. Mr Davis would be politically astute enough to know that if he did threaten to resign in writing and was then bought off with the promise of Douglas Hogg's job at the Ministry of Agriculture, public exposure of the threat could well render it ineffective. Can Mr Major really now be seen to yield to blackmail by bringing Mr Davis into the Cabinet in a summer reshuffle?

Mr Davis's appointment in 1994 to the same European Minister of State job that Mr Garel-Jones had had in the Foreign Office was pivotal. Because he came from their ranks, he was for the Eurosceptics a reassuring presence in what they saw as the all-too pliable FCO. The fact that he had a natural - and amply reciprocated - dislike for the endlessly seductive lore and culture of the Foreign Office was seen as a positive advantage.

He told colleagues that part of his job at the Florence European Union summit would be to try and stiffen the resolve of Mr Major and Malcolm Rifkind to hold out for the best possible deal - beyond the summit if necessary. It is a key post, one of the two or three senior posts below Cabinet level, and at the centre of the action. He stood in for Mr Rifkind at Cabinet when the Foreign Secretary was away; as British representative on the EU "Reflection Group" mapping out the agenda for the Inter-Governmental Conference he was a one-man awkward squad, diluting the centralism of his colleagues whenever he could.

Scarcely a man racked with self-doubt, he is said to have claimed some of the credit for the proposal to commit a future Cabinet to a referendum and for the intellectual conversion of Mr Rifkind against a single currency. With a formidable gift of the gab he has an acute political brain and an impressive academic record at grammar school, Warwick University and both London and Harvard's Business School. He makes a lot of time for insightful chats with journalists. And he is an assiduous networker across a surprisingly broad political spectrum for a man of the right; journalistic colleagues of Alastair Campbell, now Tony Blair's press secretary, were surprised to find that he was the sole Tory at a party of Mr Campbell's a couple of years ago.

He is not without his critics; one ministerial veteran of tough international negotiations says that he is not as respected as he should be abroad as a good man to do business with across the table. Another intellectual Tory said dismissively yesterday: "I've never had that high opinion of him. I've always thought he would do better on the dealing floor."

But it still looked, as Mr Davis triumphantly celebrated the Major leadership victory he had helped to create last year, that he had the ball at his feet. It now seems, though, that almost from that point something went wrong. He was disappointed that he was not rewarded after the leadership with a Cabinet job; more unusually he seems to have told colleagues so.

There may well have been real political issues at stake; it is probable that Davis thought the policy of non-cooperation, for which he argued, should have been brought in earlier. He would almost certainly have liked John Major to rule out a single currency. And he would not have been alone in despairing of the conduct of the Ministry of Agriculture in the beef crisis - or in thinking he might have made a better fist of it than Douglas Hogg. But he is also ambitious. In politics, never neglect the human factor.