The Government says it intends to press ahead with its timetable to make women wait longer before collecting state pensions, despite the threat of a backbench revolt.
The Department for Work and Pensions (DWP) has insisted that changes to the state retirement age will go ahead, warning that a delay could cost the taxpayer £10bn.
During a debate in the Commons on Monday, Works and Pensions Secretary Iain Duncan Smith faced crises of protest from all sides of the House over his timetable to reform state pensions.
MPs warned that the plans discriminate unfairly against women in their late 50s, who will now have to wait longer than they had expected to receive their pensions.
The reforms have provoked cross-party opposition, with MPs urging ministers to rethink plans to speed up the equalisation of the pension age for women and men amid warnings that hundreds of thousands of women have not had time to plan properly for their retirement.
Lorely Burt, the chair of the Liberal Democrat parliamentary party, said up to 500,000 women would be hit as they “won’t have time to plan their retirement and many will be financially a great deal worse off”.
Labour leader Ed Miliband sent out a message on Twitter, saying: “Govt plans to raise pension age by 2 yrs for 33000 women punishes the daughters, mums and grans who took time out to look after families.”
Shadow pensions minister Rachel Reeves said that ministers should bow to public pressure and rethink their proposals.
“It is simply wrong to punish women by moving the goal posts at this late stage,” she said.
“There is strong and vocal opposition to these unfair pension changes across the UK. It’s not too late for David Cameron to think again.”
David Cameron joined calls from the DWP insisting there would be no climb down over the controversial reforms while defending moves to equalise the state retirement age for men and women.
He said the Government had to be “very resolute” in making the system affordable for taxpayers. The Prime Minister said he was not seeking confrontation with unions over the changes to benefits in the public sector, and added there was room to negotiate.
With the looming thereat of industrial action, Chief Secretary to the Treasury Danny Alexander has said ministers will not back down over plans to reform public-sector pensions.
Mr Alexander made clear that while the Government is prepared to discuss the detailed implementation of the proposals, it is sticking to the broad principles which will see millions of workers having to pay more and work for longer.
Union leaders – who are planning a day of strikes across the country – have said they have to defend their members’ interests in the face of the Government’s onslaught.
On Friday Mr Alexander angered union leaders by urging members to help “shape” the current reforms now or face “uncompromising” change later.
On Sunday Shadow Chancellor Ed Balls urged trade unions not to fall into the Government’s “trap” of calling mass strikes in opposition to the proposed reforms.
Unions say a planned one-day strike on 30 June by up to 750,000 teachers and civil servants would almost certainly be followed by further mass action in the autumn unless ministers changed course.
The DWP said that ministers intended to push through the bill as planned.
“We stand by the 2016-2020 timetable for equalisation and raising the state pension age to 66,” a spokesman said.
“The bill will go forward without any changes to the timetable. If we delayed the move to 66, it would cost the taxpayer £10bn and would be an unfair burden on the next generation.”