Changes to the state pension which will hit hundreds of thousands of women aged 55-65 are to be debated again by MPs in Parliament, thanks to a high-profile petition backed by MoneySavingExpert which has now collected almost 120,000 signatures.

The new debate, to be led by Labour MP Helen Jones, will be held in Westminster Hall on Monday 1 February. Ms Jones is chair of the Petitions Committee, the group of MPs which decides if parliamentary petitions with more than 100,000 signatures should be debated in Parliament.

The changes mean women born in the 1950s will have to wait longer than expected to receive their state pensions, and many feel they have not been given enough notice to prepare for them.

The decision to hold a second debate comes as a boost for action group Women Against State Pension Inequality (WASPI), which created the petition, and its campaign, which has been gathering momentum in recent weeks.

At the previous debate earlier this month, organised by the Scottish National Party MP Mhairi Black separately to the petition, MPs unanimously backed a motion calling for extra measures to protect women affected by the acceleration in the rise of the state pension age.

However, just like the last debate, the result of the one on 1 February won't be binding on the Government, which can choose to ignore it.

Tom McPhail, head of pensions research at Hargreaves Lansdown, says the second debate is "significant", but warns it is crucial the Government responds to campaigners' concerns.

He says: "The weight and momentum which this campaign has gathered warrants a full and considered response from the Government.

"The Government may believe that no policy adjustments should be made – however it should come to Parliament, enter into debate and make its case. As part of this process, it should be possible to explore the options and costs of any potential transitional arrangement."

Why will some women lose out under the state pension changes?

There are two separate increases of the state pension age currently underway:

  • With the 1995 Pensions Act, the Government decided that men's and women's pension ages would be made the same by 2020. Previously, women retired at 60 and men at 65.
  • In 2011 the state pension age for both men and women was raised to 66.

These changes mean women born after 5 April 1950 will receive their state pensions later than expected – in some cases six years later.

Many women who had been expecting to start drawing their state pensions between 2016 and 2020 only found out in 2011 – with the additional change in state pension ages – that they would face a delay.

Some women have argued they weren't informed of the rise in their state pension age at all. And WASPI claims women affected by the changes haven't been left with much time to make alternative plans, saying that existing retirement plans have been "shattered with devastating consequences".

But the Department for Work and Pensions says it did take appropriate steps to notify women of the changes and insists "all women affected have been directly contacted".

Which age brackets are most affected?

The date on which you'll receive your state pension depends on exactly when you were born – the Government has published full state pension age timetables here. But in brief:

  • Women born after 5 April 1950 are affected by the equalisation of the state pension age to 65 (following the changes in the 1995 Pensions Act).
  • Women born between 6 April 1953 and 5 October 1954 are affected by both the equalisation of the state pension age to 65 and the rise of the state pension age to 66.
  • Women born between 6 October 1954 and 5 April 1960 will see their state pension age rise to 66.
  • The next rise in the state pension age, to 67, will apply to men and women born after 6 March 1961 (and be phased in for those born between 6 April 1960 and 5 March 1961).