Ministers and leading Tories fighting against having to reveal the outside income they earn as MPs were faced with a potential setback last night when David Trimble, leader of the Ulster Unionists, said he was in favour of disclosure.
With a dozen or more Tory MPs considering the possibility of supporting disclosure or abstaining in tonight's knife-edge Commons vote on the Nolan recommendations , Mr Trimble's remarks were the first indication that Unionists could support Labour's attempt to force through disclosure.
In an interview with GMTV, the Ulster Unionist leader was asked if he would "back John Major" by supporting the majority report of the special select committee which came down against disclosure and instead supported a ban on "advocacy" by MPs in the Commons in support of their outside commercial interests.
Mr Trimble replied: "I think that's the wrong way to look at it. It's not a question of backing someone ... This is a matter for the House of Commons. It's a free vote. John Major may have an opinion on it but he's just one out of 652 on an issue like this." Mr Trimble said he had not yet discussed the issue with his colleagues, but added: "My own preference is for disclosure. I do think that it's better for the public to know, particularly on matters like this which affect public confidence in institutions."
But although Mr Trimble's intervention was a boost for Labour's efforts to swing Tory dissidents behind them, the Opposition is not expecting anything like a full turnout of Ulster Unionist MPs and they will not be whipped in tonight's vote. They are hoping for the support of the three Democratic Unionist Party MPs and for two Social and Democratic Labour Party MPs to turn up for tonight's vote.
John Major, who made it clear last week that he would be supporting the select committee report, will not now be voting because he will be at the funeral of Yitzhak Rabin, the assassinated Israeli Prime Minister. But the political impact of this is likely to be cancelled out by Tony Blair, who is also attending the funeral and is not expected to be back in London in time to vote.
One factor that remains in doubt is whether, if the Labour amendment seeking immediate earnings disclosure is defeated, the Opposition will fall in behind an alternative proposal put by Sir Teddy Taylor, and two other Tory MPs, for disclosure to take place after the next general election.
Meanwhile, Barry Porter, Tory MP for Wirral, last night denied any impropriety in his willingness 14 months ago to enter into an arrangement with a business that approached him to arrange ministerial meetings concerning the Czech Republic.
Mr Porter was approached with the offer by a Sunday Times reporter, posing as a businessman.
"At that time this was not unusual and if it had taken place I would have declared it in the Members' Register of Interests," Mr Porter said.
The approach was revived by the reporter last week and a meeting was arranged for next Tuesday, the day after the vote, at which approaches to ministers would be discussed.