Around one million council and school support staff are set to strike this autumn after unions agreed to escalate their dispute over pay.

Unison, GMB and Unite have agreed their members will run a co-ordinated strike in England, Wales and Northern Ireland on Tuesday 14 October.

The announcement follows demonstrations on 10 July over the 1% pay rise offered to local government workers. Unions claim local government staff have seen their pay reduce in value by 20% since 2010.

While Unison pledged to engage in further strike action earlier this month, demonstrations are expected to be on a far larger scale now that GMB and Unite have also committed to walk outs.

The strike will come just days before TUC organised national demonstration on 18 October, which are also calling for decent pay.

Unions claim no further talks over pay have taken place since demonstrations in July.

Unison head of local government, Heather Wakefield, said: ‘Employers and Government must be left in no doubt that we are serious in this dispute. As sister unions, we stand together to make sure that our members are treated with decency and respect.

‘Our members cannot afford to carry on propping up local services through their pay packets. Many are low paid women who are being forced to resort to food banks and payday loan sharks just to survive. We need to put the heart back into local government by paying a living wage.’

GMB national secretary, Brian Strutton, said: ‘Our members in GMB, Unison and Unite expect us to maximise our joint effectiveness and that's why we are announcing the next strike together.

‘Our members deserve a fair pay deal and we have to fight together to achieve that. Council leaders should reconsider their parsimonious pay offer and do the right thing by their staff.’

Unite national officer, Fiona Farmer, said: ‘Local government workers have had years of real pay cuts, working harder to deliver vital local services while being paid less and struggling to make ends meet. Low paid members unable to afford basis essentials are having to choose between heating and eating. On 1 October the National Minimum Wage will overtake local government pay scales, we need Fair Pay not Poverty Pay.’

Responding to the announcement, a Local Government Association spokesman said: 'Most local government staff did not vote to strike and the vast majority did not take part in the last strike. We expect the majority will be in work as normal on 14 October.

'This year’s offer would increase the pay of most of our employees by one per cent while those on the lowest salaries would receive an increase of between 1.25% and 4.66%. This is at the limit of what councils tackling the biggest cuts in living memory can afford.

'The sooner Unison, Unite and GMB accept this pay offer, the sooner this money can reach our employees who have been waiting for it since April.' ENDS