Firefighters will stage a 12-hour strike today in the latest of a weekend of action over a long-running dispute with the Government over pensions.

Members of the Fire Brigades Union (FBU) in England and Wales walked out for five hours yesterday and will strike again between 2pm today and 2am tomorrow, and between 10am and 3pm tomorrow, forcing fire authorities to make alternative arrangements for fire cover.

The Government denied union claims that ministers had drawn up alternative proposals six weeks ago, but had been “sitting” on them ever since.

FBU general secretary Matt Wrack said: “We’re astonished that the Government would allow strikes to continue when for over a month they have been sitting on proposals that might point the way towards a solution. The ball is once again firmly in their court.

“Nevertheless firefighters simply want a workable pension scheme and an end to this dispute, and the existence of such proposals gives us hope that an end might be in sight.

“These strikes have only resumed because of a complete absence of proposals from Government. Rather than speculate on the motivations for their behaviour, now that we know costed proposals exist, we call on the minister to send us proposals without any further delay.”

The union said firefighters are having to pay higher pension contributions, face working into their late 50s before retiring and could be sacked because their fitness declines as they get older.

A spokesman for the Department for Communities and Local Government said of the FBU claims on alternative proposals: “These allegations are untrue. The proposals were shared with the FBU on March 19 and it is wilfully misleading for Matt Wrack to say otherwise.

“The FBU are fully aware that the proposals required further discussion and consideration, which the Government was committed to before the FBU walked away from discussions by calling industrial action.

“It was the union executive’s decision to call this strike that effectively ended its discussions with the Government.

“The Government is clear that further change can be made through constructive engagement, but not under the shadow of industrial action, which only serves to damage firefighters’ standing with the public.

“The deal on the table gives firefighters one of the most generous pension schemes in all the public sector, and the proposals protect the earned rights of a higher proportion of members than any other public sector scheme.

“Nearly three-quarters will see no change in their pension age in 2015.

“Under the new scheme, a firefighter who earns £29,000 will still be able to retire after a full career aged 60, get a £19,000 a year pension, rising to £26,000 with the state pension.

“An equivalent private pension pot would be worth over half a million pounds and require firefighters to contribute twice as much.

“This weekend public safety is our prime concern and robust contingency plans are in place to keep people protected.”