Unlike their English and Welsh counterparts, councils in Scotland are not prevented in law from establishing a single-party cabinet, for example. They are also not statutorily required to have any committees.
Mr Sinclair said any council in Scotland could tomorrow change the council's role to one of scrutiny as well as budget and major policy approval.
That 'highly attractive experimental playing field made it surprising that no councils are experimenting with cabinet government', he said.
In a speech to a COSLA conference on cabinet government, Mr Sinclair argued that the Labour Party, the government and COSLA all had a role to play in encouraging councils and providing advice.
'There is a lot of interest in the whole subject now,' he said afterwards, pointing to a recent COSLA poll which revealed that two-thirds of Scottish leaders supported the introduction of a cabinet system (LGC, 18 December). 'You wouldn't have got that sort of response two years ago.'
Mr Sinclair warned that one of the key barriers to successful cabinet government was party whipping. 'If scrutiny is to be truly effective and credible it cannot operate alongside tight group control,' he said. 'Similarly the cabinet must have some freedom of action.'