Liberal Democrat MP Norman Baker is threatening a one-man vigil to thwart any fresh attempt to exempt Parliament from the Freedom of Information Act.
Tory MP David Maclean last week accepted defeat after Mr Baker and a cross-party group of MPs blocked his Freedom of Information (Amendment) Bill.
But the bill remains on the Parliamentary order paper and it remains open for Maclean to resurrect it if the opportunity arises.
To prevent that happening, the Lewes MP vowed to remain in Parliament this Friday, when the bill is due to return to the Commons, so he could continue to block its progress.
An alliance of Liberal Democrat, Conservative, Labour and nationalist MPs last week succeeded in by sabotaging the private member's bill by tabling some 20 amendments and using up all of its allocated time during its report stage. Maclean was unable to muster the 100 MPs required by Parliamentary rules to close the debate and force a vote.
Had there been a vote on the principle of the legislation Maclean would have won, as disclosed by the way MPs voted on two of the amendments. In a free vote, 46 MPs easily defeated the six objectors.
One amendment would have required MPs to continue to disclose their expenses even if Parliament was exempted from the FoI Act.
Constitutional Affairs minister Bridget Prentice claimed the amendment would cause confusion and trooped into the lobbies with 24 other members of the government, including Media Secretary Tessa Jowell; Tony Blair's parliamentary private secretary, Keith Hill; Gordon Brown's Parliamentary aide Ann Keen; Paul Goggins; Beverley Hughes; Tony McNulty; Meg Munn; Gerry Sutcliffe, and Gareth Thomas.
Conservative shadow minister Henry Bellingham also advised Tory MPs to vote with them.
Three Labour Parliamentary aides — Martin Linton, Lyn Brown, and Mary Creagh — backed the amendment, along with Baker, Labour MP David Winnick and Tory MP Richard Shepherd. Hughes and fellow Lib Dem David Howarth acted as tellers.
Maclean claimed the bill was necessary to protect the confidentiality of letters MPs write to public bodies on behalf of their constituents, but produced no evidence to support his argument.
Winnick said Maclean appeared to have enjoyed a slice of "extraordinary luck".
"If it is to be properly defeated it will need quite a number of MPs to come in on Friday," he said.
"It will be the height of hypocrisy if Parliament, having passed the
Freedom of Information legislation, decided that we should be exempt
Shepherd, the only Tory to oppose the bill, told MPs: "My instinct is that it would do the House of Commons no good and add to the general feeling, which I profoundly believe to be incorrect, that we are self-serving – that we are more interested in our own well-being than in that of society at large."