Mark Irvine gave the warning after the publication of a study illustrating that current government spending patterns would lead to the loss of a further 12,000 Scottish council jobs and 24% increases in council tax in the next financial year.
The study, commissioned by Unison, says next year's projected 6% cuts in council funding would 'make the trauma of the last two years look like a picnic'.
Mr Irvine said: 'We are sending a letter to all local authorities, Unsion branches and Scottish MPs highlighting the scale of the problem of what is likely to happen next year if things remain as they are, and we are seeing the consequences of this in recent opinion polls.'
And referring to recent scandals, Mr Irvine said: 'We're not saying that any difficulties in North Lanarkshire and East Ayrshire don't have to be dealt with. They ought to be put right under public scrutiny. These are things the councils, workforce, and trade unions need a fair opportunity to try and deal with.'
A Scottish Office spokesman said: 'Obviously the government recognises the benfits of stable financial arrangements and there will also be a consultation paper [on top of the comprehensive spending review] to be issued in the summer as well.'