The refuse workers’ strike, which has left mounds of rubbish in central Edinburgh, has spread to more than a dozen Scottish councils, with industrial action set to hit schools and nurseries early next month. The strikes went ahead on Wednesday after a further round of talks between council leaders and public sector unions on Tuesday failed to reach any agreement on a pay dispute affecting about 155,000 council workers. Bin workers went on strike in some councils on Wednesday; others are due out on Friday, and in early September cleaning, janitorial, catering and pupil support workers in schools and early years services will strike for three days. Councils from Orkney to Inverclyde are affected. Trade union leaders have accused the Convention of Scottish Local Authorities (Cosla), the Scottish National party-led umbrella group for Scotland’s 32 councils, of failing to grasp the severity of the cost of living crisis. Most of their members earn less than £25,000 a year. John Swinney, Scotland’s deputy first minister and acting finance secretary, is due to meet union and Cosla leaders later on Wednesday to help resolve the dispute but earlier refused to accept that councils needed more money. He recently gave councils an extra £140m to help fund the better pay offer but Cosla leaders and the unions believe the Scottish government has to provide more funding to secure an end to the strikes. Speaking to reporters as he unveiled Scotland’s public spending figures for last year, which showed councils received only 1.8% more overall, Swinney said he “faced a multiplicity of difficult financial challenges and demands”. Keir Greenaway, a senior organiser for GMB Scotland, which organised the strike by Edinburgh’s refuse workers, said it was “bitterly disappointing and frankly shameful” Cosla would not discuss the unions’ demands for a single, across-the-board pay settlement. The three unions, Unison, Unite and GMB, have urged councils to agree to a £3,000 flat rate pay award, which they say would significantly help lower-paid workers. After initially offering 2% and then 3.5%, Cosla’s latest offer is 5%, with a very slightly higher rate for the very lowest paid. The unions said a percentage increase would unfairly benefit highest paid staff unless there was far greater differentials for the lowest paid. “Our members are angry about the lack of value being shown to them by political leaders and scared about the prospect of pay that doesn’t confront a cost-of-living crisis that’s getting worse by the week,” Greenaway said. The strikes have now spread to include SNP-run councils, which opposition leaders said brings the controversy closer to Nicola Sturgeon’s door. Edinburgh is run by a minority Labour administration, leading to senior SNP figures to accuse Labour of mismanagement. Mark Ferguson, the chair of Unison Scotland’s local government committee, said: “With inflation currently running at above 10% – and only set to increase – this offer would be nothing more than a significant pay cut, and one that our members simply cannot afford as they struggle to meet rising fuel, food and household costs.” Meanwhile, seven Labour, Liberal Democrat and Conservative MSPs who cover Edinburgh wrote jointly to the first minister, urging her to use an emergency budget her government is expected to announce to increase council funding, to help pay employees better. Alex Cole-Hamilton, the Scottish Lib Dem leader and MSP for Edinburgh Western, said the squalor left by the city’s bin strikes was a “disgrace”. “The strikes are a direct result of the steady, year-on-year erosion by your government of the local government funding settlement. Cosla is unable to offer workers a meaningful pay increase,” he said.