The campaign launched 13 years ago to win compensation for victims of the Equitable Life scandal has been ramped up ahead of the General Election.

MPs from all the major parties will speak at a rally in Westminster's Central Hall today which is expected to attract hundreds of members of the 10,000-strong Equitable Members Action Group.

Emag is calling on the government to "settle its debt" to 775,000 Equitable Life savers who were paid just 22p in the pound of their losses from policies that crashed in value when the mutual society almost went bust in 2000.

They had to share what was left of a £1.5 billion compensation fund after the government decided four years ago that it could not afford to reimburse the £4.3bn of identified policyholder losses, and that the lion's share of the fund would go to the 37,000 retirees already receiving their annuities.

Paul Weir, Emag committee member and spokesman who estimates his overall loss at £45,000, said: "If somebody had a cheque for £5,000 it just reminds them that they are still missing £20,000 of their own pension fund. With the economy on the mend, the Treasury should settle its debts."

The group's case for compensation is based on a 2,800-page report in 2008 by the then Parliamentary Ombudsman Ann Abraham, which found the government guilty of maladministration and injustice in its supervision and regulation of Equitable Life.

In a submission to MPs Emag argues that the 775,000 past and present members are owed the balance of £2.8bn because Chancellor George Osborne had in 2010 accepted the ombudsman's finding but said that in times of austerity "a balance had to be struck between being fair to policyholders and being fair to taxpayers".

During its nine-year campaign to achieve a pay-out, Emag twice went successfully to the High Court to overturn government rulings attempting to head off the wide-ranging report into its ­administration. The Treasury had said such matters were "outside the ombudsman's remit" while the Financial Services Authority had insisted Ms Abraham was "highly unlikely" to prove maladministration.

Mr Weir said the only reason given for not reimbursing losses in full had been "affordability constraints". He went on: "We think the time is now right to revisit that decision. The UK economy is said to be recovering and Equitable victims are not getting any younger. Many have died before receiving any payment. Equitable pensioners feel like they have received a down payment on a debt which has yet to be fully settled and which falls far short of the loss they have suffered to their retirement fund."

Veteran actress Honor Blackman, who has a pension with Equitable Life and is Emag's president, said: "After what happened to us, why would anybody in their right mind bother to save for a pension?"

The Emag report says: "The figure of £4.3bn is the agreed acknowledged debt for the failure of government regulators. The Court of Appeal this year ruled in favour of certain disabled people that had had their benefits reduced through government cutbacks, saying 'equality is not an option to be removed just because there are times of austerity'.

"Nearly one million non-annuitant policyholders, acknowledged to have lost £3.5bn directly down to regulatory failure, have been short-changed thus far by a staggering £2.7bn. They've only been paid, after a decade-long fight, just over a fifth of their losses - not fair!"

The group says payments could be phased over two or three years but there could be "no justification for closing the book on the Equitable Life saga".

It recognised "that the situation with the public finances is difficult" but said "savers and pensioners with HBOS, RBS, Northern Rock, Icesave, failed pension providers and a number of building societies have received 100 per cent bailouts at huge cost to the taxpayer".