Leaders from Unite, Unison and the GMB have also hit out at cabinet secretaries Kate Forbes, Shona Robison and Shirley-Anne Somerville, who they claim argued that council staff are “not on a par with health workers so could not expect a similar offer”.
The letter from the unions comes as all three prepare for formal industrial action ballots of their members on pay after an initial offer by Cosla was overwhelmingly rejected in March.
Council leaders had offered lower paid staff a flat rate payment of £800, two per cent for employees on between £25,000 and £40,000, and one per cent for those earning up to £80,000, capped at £800 – but it falls short of the average four per cent offered to NHS staff.
Negotiations have since stalled with Cosla arguing it does not have sufficient funds to improve the offer unless the Scottish Government awards additional money while the Scottish Government has said it has no locus in the discussions.
The trade unions state that local government workers have “gone above and beyond” in their response to the Covid pandemic and deserve reward and recognition for their efforts.
Wendy Dunsmore of Unite Scotland said: "The Scottish Government is treating local government workers as the poor relation in our nation's public services.
"It's appalling that Kate Forbes appears to be pitting local government workers against those in social care and the NHS by making clear distinctions about who is more deserving of a decent pay rise when all our public service workers are deserving.
“Homeless workers, school workers who have kept hubs open, refuse workers who have kept our streets clean, road maintenance workers who have kept our nation moving and social care workers who continue to care for our loved ones have all been totally snubbed by the Scottish Government.
"Let's remember that more than half of all local government workers earn less than £25,000 a year with the majority of those being predominantly women, and many of them have to apply for top-ups from the state to keep them above the breadline. It's shocking that they are being repaid by next to nothing."
Johanna Baxter, Unison Scotland’s head of local government, said if the comments about council staff not being on a par with health workers were true they would be “a disgrace and nothing short of a slap in the face to every single local government worker across Scotland”.
She added: "For government ministers to stand on their doorsteps and clap home care workers for their pandemic response but then in private say they are ‘not on a par’ with their colleagues in health is the height of hypocrisy and disrespect.
“If it hadn’t been for these workers our NHS would have been overwhelmed, our children left without an education and our most vulnerable left alone and without care in their own homes – these workers have put their own lives on the line and have done so on some of the lowest wages in the public sector.
“The Scottish Government is able to find money when it suits them… there should be no ‘hierarchy of the deserving’ amongst public sector workers in Scotland and local government workers deserve better than being used as a political football between the Scottish Government and Cosla”.
And Drew Duffy, senior organiser with GMB Scotland said: “This would be the second time Kate Forbes has made comments that suggest the Scottish Government has set a hierarchy in our public services.
"Before the election our carers were played-off of nurses as an excuse to keep them anchored to £9.50 an hour, and now we understand the Finance Secretary has said local government staff are not on a par with the NHS.
"The vast majority of local government staff that have worked throughout this pandemic have done so on just under or over £10 an hour and the offer on the table won’t amount to much more than an extra tenner a week in their pockets.
"It shows a total lack of value for their vital work, but a vacuous comment like this would also be totally disrespectful after everything these local heroes are doing for all of us.”
A Scottish Government spokesperson said that finance minister Kate Forbes was “in no doubt about the crucial role that local government staff play and has regularly commended them and thanked them for their efforts.”
He added: “Public sector workers – including local government staff – continue to be integral to tackling the pandemic in Scotland.
“Despite the pandemic exerting unprecedented pressures on our budget, the 2021-22 local government finance settlement of £11.7bn includes an additional £375.6m, or 3.5 per cent, for day-to-day revenue spending.
“In addition, the value of our overall Covid-19 support package for councils now totals more than £1.5bn."
He went on: “The Scottish Government is not involved in the local government pay negotiations. Pay settlements for council workers (excluding teachers) are a matter for Cosla and are determined through negotiations at the Scottish Joint Committee (SJC).
“The Scottish Government is not a member of the SJC and council pay is therefore not a matter it can intervene in. It will be for trade union colleagues to reach a negotiated settlement with COSLA.”