A bill to exempt MPs from the Freedom of Information Act is to be debated again - a week after opponents thought they had effectively killed it off.
Critics say the bill is an attempt to cover-up MPs expenses
Opponents "talked out" the private member's bill introduced by former Tory chief whip David Maclean last week.
It went to the bottom of the pile for this week, but in a rare Parliamentary quirk the six bills above it are not ready so is set be debated again.
Opponent Norman Baker said he was ready to talk out the bill again on Friday.
Mr Baker, a Liberal Democrat, called the bill "insidious" and part of a wider government attack on its own Freedom of Information laws.
He told the BBC it appeared ministers were giving the change their tacit backing.
The bill was introduced following long battles by the House of Commons authorities against being forced to reveal how much elected representatives claimed in travel expenses.
It would effectively remove both the Commons and House of Lords from the list of public authorities obliged to release information under the 2000 act, which came into force in 2005.
The bill also protects all MPs' correspondence from release and stops authorities, such as councils or companies, confirming or denying whether they have received a letter from an MP.
Mr Maclean said the law was needed to protect constituents and that travel expenses would continue to be published in future.
"When we write on behalf of constituents... we must be able to look them in the eye and say that in all circumstances what they tell us will not get out," he told MPs.
"It is like the relationship with a priest. We will write to an authority with their problem, but we guarantee that that information will not be leaked by us, or get into the public domain."
But critics say these are already exempted under the act, unless there is a strong public interest case and that data protection laws provide extra protection.
They believe the intention is to cover up information on subjects like MPs' expenses and allowances and other workings of the Houses of Parliament.
Last Friday a handful of MPs, including Norman Baker and fellow Lib Dem Simon Hughes, and Labour's David Winnick, kept the debate going for five hours, so the bill ran out of Parliamentary time.
Private members' bills start life with virtually no chance of becoming law unless they get government backing.
It is almost unheard of for a bill to have got through as many stages as speedily as Mr Maclean's has without official government backing.
Experienced Parliament-watchers cannot recall a time in recent years when a private members bill which was talked out has bounced back so soon.
Mr Winnick said it appeared that Mr Maclean had enjoyed some "extraordinary luck".
However two of the bills above it in the list may yet end their committee stage before Friday and be able to take their place.
Lord Chancellor Lord Falconer, asked about the bill's progress on BBC Radio 4's Today programme, said the government had decided that it was a private member's bill which the House of Commons should be allowed to "express a view on".
He said, that while he was a "friend" of freedom of information, the official government position was to be neutral on Mr Maclean's bill.
The office of Labour MP Brian Iddon, whose Pedlars Bill is due to be debated on Friday, said the Freedom of Information Bill had "precedence" under Parliamentary rules.
The latter is at its "consideration" stage - nearer to becoming an act - while Mr Iddon's bill is still at its second reading stage, it was added.