More than 1,200 firefighters in Greater Manchester are facing getting sacked and made to reapply for their own jobs with new 12-hour shifts, according to a union. The Fire Brigades Union has reacted angrily to plans by Greater Manchester Fire & Rescue Service (GMFRS) to sack all of its firefighters using Section 188 of the Trade Union Labour Relations (Consolidation) Act 1992, then only reinstate them if they agree to the change of working conditions.

According to the union, the arrangements would see around one in five firefighters' posts getting slashed, with the remainder having "worse conditions imposed on them" and seeing their families less due to their 12-hour working days.

GMFRS said it had no plans to make anyone redundant but is introducing the new shifts as part of plans to save money following government funding cuts.

Greater Manchester brigade secretary Gary Keary said: "We are staggered that GMFRS would jeopardise relations with its workforce in this aggressive way.

"To start the process for dismissing firefighters to then simply re-engage them on an un-negotiated contract is really appalling, and a serious breach of the agreed mechanisms for industrial relations in the UK fire and rescue service. We at the FBU will do everything we can to resolve what could turn into a bitter and damaging dispute using agreed procedures. Since the notice of the sacking proposals was issued, we have been contacted by lots of angry FBU members.

"We will continue to consult with them regarding the best way forward. This is the third change to shift systems in Greater Manchester since 2006 – surely firefighters are entitled to some sort of stability in their working lives."

Councillor David Acton, chairman of Greater Manchester Fire and Rescue Authority, said: "Government cuts of £28m ($36m) over the last six years have meant a reduction of over 400 firefighters from the frontline in Greater Manchester as well as significant back office cuts.

"The authority faces a further government budget cut of £14.4m over the next four years. The scale of these government cuts has left us with no alternative and no change is not an option.

"Our ultimate aim is simple - to ensure as many fire engines as possible are available when we have the most incidents and are able to get to people as quickly as we can.

"To achieve this we are already taking a third of the cuts from senior management and the back office, but we have developed a new shift duty system for firefighters which changes from a day shift of 10 and a half hours and a night shift of 13 and a half hours to two equal shifts of 12 hours.

"This system saves almost £10m whilst retaining 32 more firefighter jobs on the frontline than would be possible by trying to maintain our current system, providing up to 56 fire engines to our communities when they need them the most."