According to PricewaterhouseCoopers private sector workers will need to contribute 37% of their salary into their pension to match their retirement income paid to public sector workers on similar earnings.

According to PwC, private sector workers in defined contribution schemes typically receive employer contributions of around 6pc of salary.

For civil servants, contributing only 1.5pc of their salary to their final salary pension schemes, the implied employer contribution rate could be as high as 35.5pc of salary, the accountant said.

PwC compared the financial fortunes of a public sector employee who remains in civil service employment from age twenty-one to retirement at age sixty with someone born in the same year, who spends his whole working life in the private sector. The public sector worker would receive a pension of £28,900 compared to just £11,600 for the private sector worker.

PwC’s figures reinforce the sense of injustice of the “pensions apartheid” dividing public sector workers with well-funded final-salary pensions and private-sector staff which are having to rely on the less generous defined contribution pension schemes more.

Defined contribution schemes (DC) are fundamentally different from final salary schemes. With a DC scheme, the pension you get is dependent on how much you and your employer put into the fund, the performance of stock markets and annuity rates.

Liberal Democrat Shadow Chancellor, Vince Cable said: “This report raises further concerns about the longer-term affordability of public sector pensions, particularly for top paid public sector workers. The rising cost of public sector pensions is an area which will need to be tackled as the budget deficit continues to rise.

“While pension rights that have already been accrued must of course be honoured, going forward there needs to be an honest and open debate about the long-term affordability of public sector pensions in their current form.”