The Government has announced changes to the planned increase in the state pension age, saying that tens of thousands of women would benefit at a cost of more than £1 billion.
The Department for Work and Pensions said a plan to raise the state pension age to 66 in 2020 would be delayed by six months from April 2020 to October 2020.
Around 245,000 women and 240,000 men would benefit, including 33,000 women who would have experienced a two-year rise in their state pension age, said the Government.
The Pensions Bill going through Parliament would be amended from the current timetable to cap the increased wait to a maximum of 18 months, costing the Government £1.1 billion.
Under the Bill, the state pension age for women would reach 65 by November 2018 and rise to 66 for men and women by April 2020.
Work and Pensions Secretary Iain Duncan Smith said: "We have listened to the concerns of those women most affected by the proposed rise in state pension age to 66 and so we will cap the increase to a maximum of 18 months. We have always made clear that we would manage any change fairly and ensure any transition is as smooth as possible."
Prime Minister David Cameron's official spokesman said that the changes were intended to make the transition to the new system "as smooth and fair as possible".
"The policy of increasing retirement age and equalising retirement age remains, but we have acknowledged the fact that there were some transitional issues with that change and we have been looking for some time at how to deal with those," he said. "We are acknowledging that if we make these changes there are going to be different effects on different people depending on how old they are."
Shadow Work and Pensions Secretary Liam Byrne said: "This is a humiliating climbdown for David Cameron, who has ordered his ministers to rush out an 11th-hour change to his Pensions Bill which faced a storm in Parliament next week. Today's announcement is just a sticking-plaster, and hundreds of thousands of women will still have to work longer and lose thousands without enough time to prepare."
Michelle Mitchell, charity director of Age UK, said: "We would have liked the changes being made to have gone further. Having faced uncertainty twice already, these women must not be affected by any further changes to their state pension age again without sufficient notice."