The last Labour government ruled out introducing the so-called bedroom tax when it was in power, senior party sources have said.

Labour ministers rejected the housing benefit cut, believing it would do little to ease council waiting lists.

The policy, subsequently brought in by the Tory-LibDem Coalition, has proved immensely controversial.

Coalition ministers say it is necessary to encourage those with a spare bedroom to downsize and free up housing for others.

But figures released by councils last week showed there are houses available for fewer than one in 10 affected households. Last month, the Department for Work and Pensions announced it was doubling funds for those struggling with the tax to £65 million.

Reports suggest that Labour could pledge to scrap the bedroom tax if it wins the next general election, due to be held in 2015.

But it can be revealed that the benefits cut was kicking around the Treasury when Labour was last in power. It is understood the bedroom tax was suggested to Alistair Darling when he was the Chancellor.

Sources close to Mr Darling said: "It was an idea that was suggested in his day. But he rejected it. Housing just doesn't work like that. There are not magically all these one-bedroom flats for everyone to move into."

The Coalition has already come under fire for agreeing cuts suggested by the Treasury, often with disastrous consequences. Former Labour spin doctor Damian McBride has revealed many of the most contentious items in George Osborne's "omnishambles" Budget had been rejected out of hand by the previous Labour government. They included a number of policies on which the Chancellor was forced to perform U-turns, such as the "pasty tax" and "church taxes".

Although it was only introduced earlier this year, the bedroom tax was announced in George Osborne's 2010 emergency budget, just months after the Coalition came to power.

Housing charities warn it is already leading to higher levels of rent arrears and will create homelessness. The Scottish Government has estimated it affects around 52,000 homes in Scotland.