Barber said: "If Francis Maude had genuinely wanted this idea to be taken seriously I would have expected him to have raised it directly with the TUC and unions rather than play it as a PR gambit in a press interview.

"The way to resolve this dispute and avoid industrial action is to make real progress and acceptable offers in the negotiations. Francis Maude seems to want to divert attention away from the government's failure to make proper offers in scheme negotiations.

"Ministers had better make their mind up whether they intend to negotiate genuinely in good faith or through the megaphone of media stunts." More information on the TUC's pensions justice website.