Nicola Sturgeon is to chair talks with union leaders this afternoon in a bid to end the council workers’ strike.

The SNP leader's intervention comes as the first tranche of strike action comes to an end and the clean-up operation gets underway.

Local authorities have mountains of rubbish piling up on their streets to tackle. 

Both Glasgow and Aberdeen councils have warned residents to expect a significant delay to all bin collections due to the extensive backlog of work.

That backlog could yet grow.

Unless there is a breakthrough in the talks, refuse workers will walk out for eight days next week.

They will be joined by some colleagues in schools and early years workers, with union members taking part in a three-day protest in some areas.

Ms Sturgeon has already warned that all options for making more funding available for pay have been “exhausted”.

The First Minister tweeted: “If we could go further we would, but @scotgov budget is finite.”

The latest offer, made by Cosla on Monday, was rejected as unions urged it to make a flat-rate deal as opposed to one based on a percentage increase to current wages.

According to the Scottish Government, the offer included a payment of at least £1,925 for council staff, with those earning £20,000 receiving £2,000.

But Unite said the payment could be as low as £989 for some employees, with 85% receiving between £1,925 and £2,000, and any payment would not be recurring.

Unite's regional officer, Wendy Dunsmore told BBC Radio Scotland that she will use the meeting with the SNP leader to demand a “fair and decent pay rise for all workers”.

She said: “We’re hoping she is intervening to get a resolution to this crisis we are in.

“Our members don’t want to be on strike any more than anyone else would want our members to be on strike, but that is the position they have been forced to take.”

Unions have already rejected a 5% pay rise offered by local government body Cosla, with Ms Dunsmore insisting the current offer shows “disregard for the lowest paid”.

She continued: “What we want is a fair and decent pay rise.

“Our claim is £3,000 flat rate. Right now they are offering £2,000 to the highest-paid workers, but for others they are offering far less, but with a cash incentive or a cash payment.

“The cash payment will disappear quite quickly with tax and insurance. If I was Cosla or the Scottish Government I would definitely look at consolidating that into pay because then it would be worth something today, tomorrow and in the future.”

If no deal can be reached, Ms Dunsmore said unions – who have already warned of a possible winter of discontent – could escalate their action.

“The industrial action next week is three days in schools and early years, and in waste is eight days,” she said.

“What happens after that is the unions will regroup and will look to escalate this further, so that could have further impacts on services across Scotland.”

She added: “Our members are very resolute on what they’re looking for, they cannot afford to work in poverty. So we’re having to make plans and a strategy as to meet the needs of our members.”

Ms Sturgeon's political rivals criticised the First Minister for taking so long to get involved in the negotiations. 

The SNP leader has been mocked for taking part in five different shows at the Edinburgh festivals.

Her final appearance was on Monday evening with an interview with the Succession actor Brian Cox.

Scottish Tory leader Douglas Ross tweeted: "Breaking News!  The Edinburgh Festival is over so Nicola Sturgeon now has time to deal with the mess she’s made of Scotland…"