Equitable Life's remaining 345,000 policyholders will get a 25% boost to their policies next month, while the 5% exit penalty for leaving the society is finally removed.

The effective 30% uplift in value for anyone wanting to transfer out of the society, which came close to collapse in 2000, means exit may now be a more attractive option.

But for up to 8000 pensioners now in their eighties who took out an Equitable Life pension before September 1992, many suffering losses in the tens of thousands, the £5000 cheque received recently is all they will get.

Leonard Sculthorp, 83, a retired chartered accountant from Glasgow, has been writing to politicians in disgust at the continuing exclusion of the oldest pensioners from the government's pay-out schemes for EL policyholders.

Mr Sculthorp took out two plans with EL in March 1991, when the society was raking in assets based on its boasts of mutual probity, low costs, and high annual pay-outs. One policy was a 'without profit' version, in which he invested £100,000, where his income has trebled.

The other was a 'with-profit' version, where he invested £170,000, and his income has halved since 1991. Mr Sculthorp calculates that had all his savings been put in the 'without-profits' plan, he would today be better off to the tune of more than £226,000. He says EL was "one of the largest life assurance companies, supposedly regulated by the government". His appeals to politicians have fallen on deaf ears, as has a plea to the ombudsman to intervene.

Mr Sculthorp says: "It seems very wrong that the final guardian of justice, the ombudsman, is now either unable or unwilling to take up our cause."

In 2008, after an eight-year campaign by Equitable Members' Action Group (EMAG) in the courts and in parliament, the parliamentary ombudsman found the government guilty of maladministration, in a 2800-page report.

In 2011, the government decided to award 100% compensation to those who took pensions after September 1, 1992, and nothing to those who retired earlier.

EMAG commissioned an expert report from Scottish actuary David Forfar which found a "remarkable consistency of losses" between both groups, with most seeing their pension income cut by 60% and going down every year. The action group's campaign to reverse the decision, fronted by actress Honor Blackman, prompted the government to announce a year ago that all those excluded would get a £5000 cheque, and payments have been going out this year.

Paul Weir, spokesman for EMAG, which has boasted 50,000 members, commented: "EMAG's policy remains that the pre-1992s should be treated on exactly the same basis as post-92s, and awarded a properly-calculated amount based on the same formula. The £5000 is a down-payment."

The Equitable Life Payment Scheme, paying out less than one-quarter of their losses to all other EL victims, has one year to run.

MrWeir said: "We are ramping up our campaign to persuade MPs that 22.4% of our acknowledged losses is not enough. We want them to settle the debt on the missing 77.4%. We were originally told the amount was capped for 'affordbability' reasons. If the economy is improving, that reason no longer holds."

Meanwhile those still in the society, with a pension or perhaps a with-profits bond, have to decide whether to hang on or come out. Equitable said this week: "We intend to continue to reduce the society's risks and, if these plans are successful, our hope is that the capital distribution will increase."

Danny Cox at Hargreaves Lansdown says: "When transferring, you must be confident the performance of the new pension or investment product will make up any costs of moving and perform at least as well, if not better. Certain policies include perks such as guaranteed bonus rates of up to 3.5% per annum or extra tax-free cash, which could be lost on transfer. Risk-averse investors might take some comfort from the cash like return the with-profits fund provides."

Patrick Connolly at advisers Chase de Vere said: "If you are in the home straight with 10 years or say five years left to go to maturity, it is likely to be in your interests to remain invested."

Mr Weir said: "I guess the choice is between the bird in the hand today, or taking a punt on what the future [holds]."