The UK government has been urged to immediately introduce transitional arrangements for those women negatively affected by increases in state pension age, after losing out on a vote in a debate in the House of Commons.
Led by Scottish National Party MP Mhairi Black, the debate highlighted concerns around the decision to accelerate the rate at which women's state pension age is to be equalised with men's, without adequate notification.
The backbench motion called for the government to implement transitional measures, with 158 votes in favour and 0 against.
The debate was organised by the Backbench Committee but it coincided with an online petition created by the campaign group, Women Against State Pension Inequality (WASPI), which requested the government to address the issue. The petition has won more than 100,000 signatures.
Black welcomed equalisation but criticised the government's measures to notify women affected by the change.
She said the Pensions Act 1995, which set out pension age rising from 60 to 65 between 2010 and 2020 was "fair enough" because it would give women 15 years of notice. But there had been little media coverage about the move, and many women were not aware of the change.
According to a freedom of information request response, the Department for Work and Pensions (DWP) only wrote to people between 2009 and 2013.
Black added that the Pensions Act 2011, which accelerated pension age equalisation by raising the age to 66 from October 2016, meant that those women affected "had only five years' notice to try to remedy life plans that had been in place for years".
"In civil law, if we enter into a contract, there are terms and conditions stating, 'If you want to change this contract or break out of it, there will be a price to pay'", she said.
"Why are pensions any different? This is a contract people have entered into, but it is now being broken and nothing is being done to allow them to transition."
Backbench motions are not legally binding on the government but simply an opportunity for the House to express its will.
The petition could potentially lead to another debate after securing more than 100,000 signatures. However, the House of Commons Petitions Committee is yet to confirm whether further discussions are to take place.
Sarah Pennells, founder of the financial website SavvyWoman, said there was "a long way to go" and WASPI may have to press the issue further.
"This is just the first stage. I think we will see renewed pressure in terms of what the committee decides, which could be next Tuesday or it could be picked up the weeks after," Pennells said.
"There is a long way to go. The fact that there's a 158 to nil is a good sign. But I think they have to prepare for quite a fight because it will cost the government money and they don't want to do that."
The DWP did not comment on whether the result of the debate would trigger any changes, but a spokesman said: "The existence of different state pension ages for women and men represents a longstanding inequality, and the abolition of this discriminatory situation is long overdue.
"The last government introduced future changes to the state pension age for women and men, following extensive debates in both Houses of Parliament."