Cosla's Alison Evison will warn of "increasing centralisation of services and national policy direction" when she addresses the body’s virtual conference.
In a speech, Ms Evison is expected to say: "The erosion of our core budget is probably the biggest single challenge facing local government today.
"I remain positive, however, and hope that the erosion of local government’s core budget is something that can be addressed through joint work on a fiscal framework – the rules around our funding relationship with Scottish Government.
"We expect progress on this in the upcoming spending review to achieve more stability, certainty and transparency as well as more local discretion on revenue raising in order to allow us to make an even bigger impact and difference on the ground in communities across Scotland.
"Sadly, in Scotland we are continuing to see an increasing centralisation of services and national policy direction, including a growing level of ring-fenced and centrally directed funding."
Ms Evison will highlight proposals for a National Care Service in Scotland, which Cosla has criticised.
She will add: "Centralisation is the enemy of everything we stand for in local government.
"It does not lead to efficiency and effectiveness. It leads to increased cost, inflexibility, an inability to respond to local requirements and lesser outcomes for communities.
"All of this in the context of a Budget for the next year, described by many council leaders as the worst they have ever seen and which led our council leaders to come together in a strong letter to the First Minister."
Elsewhere, Ms Evison will pay tribute to all 32 Scottish councils coming together to support schemes for people fleeing Afghanistan.
However, she will say hotels “are entirely the wrong accommodation for people who have arrived in Scotland having left their own homes in incredibly difficult circumstances – Scottish councils stand ready, willing and able help achieve appropriate settlement”.