Ministers challenged the Conservatives and Liberal Democrats to back a package of reforms to the state pension system insisting they cannot "pick and choose" from the proposals.
Attempts to forge a national consensus on the future of pensions had a setback as Labour attacked the Tories for criticising planned cuts in benefits for carers and a scheme designed to help pensioners with a small income from savings.
The row broke out ahead of a Commons debate on the reforms, as the Pensions minister, James Purnell, wrote to the Conservatives claiming their plans would cost the taxpayer £15.5bn by 2050. But the Tories hit back, insisting they had every right to highlight the details of the proposed reforms.
In the Commons yesterday John Hutton, the Secretary of State for Work and Pensions, indicated there would be little scope to change the key proposals.
The Pensions White Paper, published last month, set out plans to raise the state pension age to 68 to fund moves to restore the link between the state pension and earnings from 2012.
The reforms would also include enrolling people on a national savings scheme, moves to boost the pensions of women and carers and reduced means-testing.
Mr Hutton told MPs; "There isn't a pick and choose menu on offer so we do not have the luxury of cherry-picking."
He urged MPs to support the Government's plans, telling the Commons: "In supporting the motion, the House can record its support for the direction of travel set out in the White Paper and in doing so help us take a significant step towards a truly lasting pensions settlement."
But Philip Hammond, the shadow Work and Pensions Secretary, said: "We support the call for a national consensus - but you can't build a lasting national consensus behind closed doors."
He warned: "It has to be a hard-edged consensus not a woolly one and you will know that the history of recent pension policy warns us of the fragility of any consensus built around a flawed proposition."Reuse content