Lawyers representing Waspi women are preparing to write to the Government challenging its decision not to offer compensation.
In January, women affected by the way changes to the state pension age were communicated were told for a second time they would not receive money.
Women Against State Pension Inequality (Waspi), which has long campaigned for compensation, said lawyers are set to raise “legal errors” with the Government and will give its lawyers 14 days to respond.
Campaigners suggested that they could take their battle to the High Court.
They argue the Government based its decision on the awareness of state pension age changes on a “narrow set of data”.
A report by the Parliamentary and Health Service Ombudsman has previously suggested compensation ranging between £1,000 and £2,950 could be appropriate for each of those affected by the way state pension changes had been communicated.
Waspi chairwoman Angela Madden said: “Women affected by the Government’s failures have waited long enough.
“If ministers will not listen to the independent ombudsman, their own MPs and millions of people across the country, we will make them listen in court.”
A spokesperson for the Department for Work and Pensions (DWP) said: “The Secretary of State set out the Government’s position in his oral statement to Parliament, including acceptance of maladministration and apology to the women affected.
“Our focus now is on delivering an action plan to implement lessons learned in how DWP communicates state pension matters going forward.”
