Union officials are considering legal action over changes to the way public sector pensions are to be indexed.
GMB officials have expressed concern that the change from the Retail Price Index (RPI) to the Consumer Price Index (CPI) could be applied to accrued benefits.
The announced change to indexation, which has not been extended to all pension calculations, came just days after the prime minister made a pledge that the commission examining public sector pensions would not affect accrued benefits.
However pension fund managers, unions and actuaries have all suggested that it could apply to accrued benefits, which would reduce the value and cost of pensions by an estimated 10%.
Brian Strutton, GMB’s national secretary for the public sector, said: “We are looking at whether it can be legally challenged, including whether RPI indexation is guaranteed or whether the accrued rates protection kicks in.”
Actuary Andrew Lowe, from Hymans Robertson, said the £6bn saving highlighted in the Budget announcement suggested that the government was talking about accrued benefits.
However, there was unlikely to be any certainty until John Hutton’s commission published its report or the Department for Communities & Local Government issued new orders for the Local Government Pension Scheme, he said.