The prospect of public sector workers losing some of their pension because of mistakes made by the government is "disgraceful", the Liberal Democrat work and pensions spokesman says.
Stephen Lloyd, the political party's MP for Eastbourne, said workers in the NHS, armed forces, teachers and thousands of local government employees, could have some of their pension "clawed back".
He said the problem has arisen because many workers who were contracted-out have now been found to have received an overpayment - something he says was "no fault of their own".
Lloyd said government departments with affected workers must now chose whether or not to "clawback" the overpayments - and has written to the secretaries of state for health; education; and housing, communities and local government to urge them not to claw back the pension over payments.
He said: "I think clawing back the pension overpayments would be this government profiting from its past failures."