Gordon Brown has imposed a three-line whip to force a move to block full publication of MPs' expenses through the Commons, The Times has learnt.

Labour MPs could face sanctions if they rebel in tomorrow's vote on an amendment to the Freedom of Information Act that would exempt MPs from disclosing exactly how they have been spending their annual £22,000 second-home allowance.

Public opposition is growing against the move, with almost 5,000 people signing a Facebook campaign led by mySociety, who run the “theyworkfor-you” website, to urge MPs not to push through the change.

Yet the amendment is almost certain to be passed. An early day motion tabled by the Liberal Democrat MP Jo Swinson, opposing the change, has been supported by only 11 MPs.

The Commons had been on the brink of publishing receipts for every claim made by an MP since 2005 after losing a High Court battle last year.Instead, Harriet Harman, the Leader of the House, announced last week that expenses would be published under 26 general headings, an increase from the current 13. The information will be broken down into “fixtures, fittings and furnishings” and “other household costs”, with no specific detail about what has been bought.

The process of scanning more than a million receipts for publication, which has cost hundreds of thousands of pounds, will be abandoned.

Both main opposition parties have said they oppose the move. The Tory front bench will vote against the change, with other MPs being urged to follow their lead. All Liberal Democrat MPs are under a three-line whip to vote against.

One Labour MP considering rebelling said that doing so posed considerable risks. “Not only could you face sanctions from the whips, I would also face considerable sniping from colleagues if I tried to oppose this,” he said. “You have to watch for the blade between the shoulders.”

Nick Clegg has been the only party leader to speak out against the change, with both Mr Brown and David Cameron more cautious.

Mr Clegg said: “At a time when families are having to count every penny, it is outrageous that MPs are seeking to hide how they spend their money. The Liberal Democrats are totally opposed to any government move to allow MPs to avoid being subject to Freedom of Information requests.”

Mr Brown's spokesman referred all inquiries to Ms Harman. He added: “The aim was to finish up with a system that was more transparent.”

MPs against the amendment

Labour

Frank Field

Mark Fisher

Kate Hoey

David Winnick

Conservative

Richard Shepherd

Peter Bottomley

Lib Dem

Adrian Sanders

Jo Swinson

Evan Harris

Steve Webb

Bob Russell

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