On behalf of 104,000 members in Prospect, Assistant General Secretary Dai Hudd, said:

"This is a breakthrough that vindicates the stand taken by our members all year. An imposed retirement age of 65 would have broken contractual terms and threatened to cause uproar among specialists in all grades.

"The precise terms for central government staff have not been worked out and will depend on the scheme-specific negotiations which have yet to begin. But the principle that existing staff should suffer no detriment to their pension age or entitlement is now accepted, and we welcome that protection."

In the talks on the civil service scheme, Prospect will seek flexibility for existing staff to move to the terms planned for new entrants where that would be better suited for both employee and employer.