The coalition government has been accused of targeting northern towns and cities with cuts after today's announcement that 2,000 jobs are to go at Manchester city council in the next 12 months.

The GMB trade union, which has been tracking notifications of job cuts, says that more than 113,000 town hall jobs have been declared "at risk" by 145 councils and police and fire authorities, with another 350 yet to declare.

Manchester council's jobs announcement – which will affect 17% of the council's 12,000-plus non-schools workforce – was triggered by the government-imposed cuts to its budget of more than than 20%.

It comes at the end of a bleak week for the north-west public sector in which it emerged that police authorities in Lancashire, Cheshire and Merseyside have earmarked 3,200 jobs as "at risk".

More than 24,000 council jobs now face the axe in the north-west, according to GMB figures. These include 800 at the council in Oldham, where voting takes place in a parliamentary by-election today. In addition, hospitals in central Manchester warned they may have to cut 1,400 posts over the next four years.

Labour politicians claimed the region was shouldering a disproportionate burden of the cuts. Council leader Sir Richard Leese, said: "The unfairness of the government's financial grant settlement for Manchester, one of the worst in the country, has been widely reported.

"We now have to find £110m in savings next year – £60m more than expected – because of front-loading and the re-distribution of money from Manchester to more affluent areas.

"The accelerated cuts mean we can no longer achieve the staffing reductions we have been forced into through natural turnover."

Many councils in the most deprived areas – in the north-west, north-east and the Midlands and inner London are angry at the speed of the cuts and the way coalition changes to the way cash allocations are distributed has left the poorest areas with millions of pounds less than they anticipated.

They have criticised as "smoke and mirrors" communities secretary Eric Pickles' claims made last month that council "spending power" cuts would be capped at 8.9% next year. Manchester says that although the "official" cuts to its budget amount to 16% over two years, the removal or reprofiling of specialist grants means the real terms cuts to its budget could be nearer 25% over the same period.

Workers at all grades and in all departments at Manchester council will be affected by the cuts, including street cleaners, social workers, administrators, managers and accountants. Only those involved in teaching will be exempt.

Council officials say they are being forced to save £110m this year alone. They were today outlining the plans to staff, who will all be given the chance to apply for voluntary redundancy and early retirement. Sources said workers would be offered 'very attractive' terms in a bid to hit the massive jobs-cut target. Staff will be given a few months to apply for the deals. Bosses are currently finalising details.

The bill for pay-offs will run into many millions of pounds, although the council says the redundancies will will save £70m every year.

The council insists it still hopes to avoid making compulsory redundancies. But they admit the scale and speed of the cuts means they cannot give any guarantees.

The plans will go to the council's executive committee for formal approval next week.

The council learned last month it would lose 21 per cent of its government grants over the next two years – the seventh worst settlement in the country.

Remaining staff may be transferred to different parts of the town hall. The council is one of the biggest employers in Greater Manchester.

Paul Kenny, GMB General Secretary, said "The announcement by Manchester city council of 2,000 job losses as a direct result of the cuts announced by the coalition government is proof that the job losses that the GMB have been reporting in councils across Britain are real. They impact on real workers and impact on the services delivered to the most vulnerable members of our society."

The Unite union raised the threat of industrial action to fight the planned cuts. Regional officer Keith Hutson said: "Unite members will be considering a consultative ballot for industrial action to stop these cuts to a hard-working and dedicated workforce, providing important services to the community."