Prospect Deputy General Secretary Dai Hudd said: “This is an arbitrary announcement, which has been made without consulting the unions.

“Our members did not ask for bonuses, which in most cases are a substitute for a pay award. They want to be paid the proper rate for the job that they do. But bonuses were introduced by the Treasury in the 1990s as part of a government policy designed to make departments more ‘business-like’.

“It’s all very well for Danny Alexander to complain about them now, but it’s the politicians and Treasury officials who drove forward this agenda, introducing arrangements that in many cases replaced genuine pay increases.

“For members of Prospect, who are middle managers, professionals and specialists, most of the sums involved represent hundreds of pounds a year, not thousands. It’s ludicrous to compare these amounts with the vast bonuses that bankers and other top managers receive.

“That debate should not be used as a smokescreen to whittle away even more at civil service pay, at a time when members already face pay freezes and pension increases. All it shows is that a full-scale reform of civil service pay arrangements is long overdue.”