Ministers are to signal this week that they are prepared to bust the 1% pay cap for police and prison officers, as a first step towards recognising the concerns of cash-strapped workers across the public sector.

In a significant shift that was already being claimed as a victory by trade unions on Sunday night, Downing Street has indicated that it is time to consider easing the pay freeze imposed in 2010 by then chancellor George Osborne.

The government is expected to accept the recommendations of pay review bodies for the police and prison service, which are due to report soon – a move likely to increase the pressure for real-terms rises for nurses, teachers and other key public sector staff.

Rehana Azam, national secretary of the GMB union, said: “The artificial cap on pay was always a political choice by the Conservative government. This cruel policy has seen thousands of pounds pinched from public sector workers over seven years.”

Labour’s shadow policing minister Louise Haigh said the shift in policy was long overdue, with Labour research suggesting frontline police officers are now £6,000 a year worse off in real terms than in 2010.

“Ministers have spent seven years asking the police to do ever more while slashing their pay year after year, leading to rock bottom morale and skyrocketing resignations,” she said.

“We hope that ministers will finally listen to us and agree a fully funded and fair pay settlement for police officers this week but they must not simply put the financial burden on already over stretched police budgets.”



However, it was unclear how extra funds would be found, and whether all police and prison officers would receive pay rises above the board, or only some would benefit. Pay has been frozen or capped across the public sector since 2010.

The move comes as Labour prepares to force a vote on the pay cap in parliament on Wednesday. At the TUC’s annual congress in Brighton on Sunday, John McDonnell pledged Labour’s support for workers who strike over the policy.

The shadow chancellor told union activists that the party’s senior figures would join strikers on picket lines if they took on the government against a policy that has led to a 14% real-terms cut in wages over the past seven years.

At the launch of the annual TUC gathering in Brighton on Sunday, union leaders announced campaigns to press ministers into lifting the cap for all public sector workers.

Dave Prentis, the head of Unison, which represents thousands of nurses, said his union would target 27 Tory MPs in marginal seats in an effort to end the 1% limit on pay rises.

Four unions have tabled motions calling for nationally coordinated action. Civil servants who are members of the Public and Commercial Services (PCS) union are to be balloted over possible strike action in the run-up to Hammond’s autumn statement.

McDonnell spoke after it emerged that Labour would lead a debate on public sector pay in the Commons on Wednesday. At a “Fight together for a pay rise!” meeting organised by the National Shop Stewards Network, he said Labour would stand alongside striking public sector employees.

“Let me make it absolutely clear. You have the democratic right to ballot for industrial action and if as a result of those ballots you support industrial action – I tell you this on every case we have seen so far it has been just – and therefore yes, we’ll be in parliament supporting you and we’ll be on the picket line supporting you as well.”

He said there would be no need for strikes if the government scrapped the pay cap and introduced a pay strategy that enabled people to have a real living wage.

He implied that he would support coordinated union action. “If you decide that you’ll take that action democratically together, you will have our support, because this struggle is about whether or not they push more and more working class people into low wages, poverty, debt and insecurity,” he said.

Prentis told a press conference that the government should not try to “cherry pick” some public sector workers for pay rises. He said it would be disastrous for public services if some groups of workers were given rises at the expense of others.

Unison pointed out that it had 2,000 members in Southampton where the Conservative MP Royston Smith has a majority of 31, and 2,600 members in the Pembrokeshire seat of Stephen Crabb, who won by 314 votes.

The PCS leader, Mark Serwotka, will urge other unions to hold consultative ballots with their members over possible industrial action.

A motion before congress on Monday which calls for coordinated campaigns over the cap is expected to be carried unanimously. Serwotka will speak in favour of the motion and say that it should be backed with ballots to let the public and the government know that this time the unions mean business.

He said that if the government tried to give a pay rise to the highest paid civil servants, as has been previously reported, it would provoke greater support for industrial action.

“If the government was stupid enough to just make concessions to the very top civil servants, we would be weighing the votes in our ballot. If you selectively decide that the best paid are the ones who get the first concession, it would not feel right to me or anyone else,” Serwotka said.

Speaking just before McDonnell, Len McCluskey, the head of Unite, Britain’s biggest union, said it had coordinated a “massive strike fund” of £36m to take on employers.

“We wanted to send out two messages. Firstly to our members, to say we are not going to allow the bosses to starve you back to work and secondly to send a message to employers to say ‘if you think you can starve our members back to work then you better think again’,” he said.

He reiterated past claims that Unite was prepared to break the law to take on employers and the government. “We will stand shoulder to shoulder with any workers in struggle,” McCluskey said. “That is why we took the issue out of our rule book about always acting inside the law. We took that out because we know that if the bosses and the privileged elite want to push us outside the law, so be it. It won’t stop us standing up.”

Ronnie Draper, head of Bakers, Food and Allied Workers Union, told shop stewards: “We should be balloting for a general strike. Every single worker in this country will have a beef against their employer for some reason.

“We can take part in a general strike that is coordinated. There’s nothing illegal about it. Nothing the government can do about it.”

The defence secretary, Sir Michael Fallon, said last week that the government understood that civil servants, teachers, health workers and council staff had taken their “share of the pain” of deficit reduction and indicated the chancellor was looking at the issue.