A report into how increases in retirement ages have affected women is expected to be published on Thursday.
The Parliamentary and Health Service Ombudsman report follows campaigning from women who saw their retirement age aligned with that of men.
Women Against State Pension Inequality (Waspi) say millions have lost out due to the change and campaigned for compensation after retirement plans were harmed by the change.
🚨PHSO is set to publish its final report tomorrow after a 67 month investigation.
If the PHSO has treated evidence from #WASPI women with the same weight as government's representations, he will have no choice but to suggest significant compensation for WASPI women. (1/5)
— #WASPI Campaign (@WASPI_Campaign) March 20, 2024
Women born in the 1950s were told they would have to wait longer for their state pension when changes to the state pension age to equalise it across genders were accelerated in 2010.
The pension age for both men and women is set to rise again from 66 to 67 between 2026 and 2028.
The ombudsman has been investigating the issue for five years with the first stage, published in 2021, saying the Government was slow in informing women how they would be affected by the change.
The next part of the report could make recommendations on compensation.
Waspi chairwoman Angela Madden told the BBC: “It is now for each political party to put their money where their mouth is and support compensation of that order.
“Waspi women are watching and waiting to see whether politicians who have long supported the campaign will now deliver.”