Official figures revealed by the Liberal Democrats show that the value of Government ministers’ taxpayer-funded retirement funds has risen by 10 per cent this year.

In contrast private workers pension funds are estimated to have fallen by as much as a quarter as stock markets and interest rates fall.

Some senior ministers are entitled to pension funds of more than ten times the average workers’ private retirement fund.

The average private pension fund has a value of around £25,000 and because of falling annuity rates, this pension fund will only generate an annual income of just over £1,600.

Gordon Brown may have given up his entitlement to a larger prime ministerial pension, but his Cabinet minister’s fund is still worth £274,000, which is still enough to deliver an annual income of more than £19,000.

Jack Straw, the Justice Secretary has the largest fund which is worth £294,000, and Alistair Darling, the Chancellor and the other member of the cabinet to have served since 1997, has a fund worth £235,000.

Ministers contribute to their pension funds, but the largest contribution comes from the Treasury, which contributes 26.8% of a minister’s salary into the fund.

Minister’s pensions are paid in addition to any pension a minister builds up as an MP.

The figures taken from departmental accounts, show ministerial pensions have a “cash equivalent transfer value” of £7.4 million.

Lord Oakeshott, the Liberal Democrat Work and Pensions Spokesman, said: “Taxpayer guaranteed, index-linked ministerial pension pots shot up by a tenth last year, but private pension pots have plummeted, typically by a quarter in 2008.

“Ministers and mandarins live in a pensions time warp.  They look like the First World War General in Blackadder, sipping fine wines in a chateau well behind the front line while privates in the trenches get their pensions shot to pieces.”

Senior civil servants have also seen their pension funds increase healthily.

Leigh Lewis, the senior civil servant at the Department of Work and Pensions saw his pension pot rise by £314,000 from £1,567,000 to £1,881,000.

Lord Oakeshott said that was proof that top public sector pensions are “clearly out of control”

Earlier this week, the Daily Telegraph disclosed that public sector pensions are set to rise by five times next year’s rate of inflation.

Pensions experts have warned of a growing division between public sector workers with well-funded final-salary pensions and private-sector staff with much less generous retirement schemes.