The party's social security spokeswoman, Liz Lynne, said the Christmas bonus was "an insult which we want to redress by paying a double pension in the first week of December".
But within minutes of publishing a policy document on the elderly saying it was party policy to give pensioners a double pension in the first week of December, officials were stressing it was not a commitment.
"It is still in the running to get into the manifesto but we are having a costing exercise. Whether it will get in, we cannot say yet," said an official.
Officials also had to correct Ms Lynne's figures after she told a news conference it would cost pounds 580m to implement. The real estimated net cost was pounds 440m, after deducting the cost of the pounds 10 bonus, which would be scrapped.
The confusion over Ms Lynne's apparent pledge follows strains between the Rochdale MP and the Liberal Democrat leader, Paddy Ashdown, over his strategy for moving closer to Labour, which she opposes. Officials denied the launch of the policy document, A Fair Deal for Older People, was being used as a lever to force a higher spending policy on the Liberal Democrat leadership.
Harriet Harman, Labour's social security spokeswoman, set out Labour's alternative with a boost to occupational pensions, through "stakeholder pensions".
It came as the Treasury last night was accused by Labour of drafting slap-dash legislation on the budget in an attempt to close tax loopholes in the run-up to the general election.
After securing a series of concessions from Phillip Oppenheim, the Exchequer Secretary, Dawn Primarolo, the Labour spokeswoman said: "The wheels are falling off the Finance Bill and it shows that the Bill was badly drafted."
Alistair Darling, the Treasury spokesman who is leading for Labour on the Bill, said many of the problems arose from a note sent to Customs and Excise by William Waldegrave, the Chief Secretary to the Treasury, seeking suggestions on increasing the tax revenue.
Liberal Democrat attempts to water down proposals to legalise the "bugging and burgling" of private property by the police were defeated by a huge majority in the House of Commons last night, writes Fran Abrams. Ministers had retreated after a Lords defeat and had promised that police must seek prior approval from government-appointed security commissioners in all but the most urgent cases.
The Liberal Democrats, who believed that judges should approve the action, were supported by some Labour MPs led by Tony Benn. The motion was defeated by 264 votes to 41.Reuse content