Members of the joint DoE/council IT competition working group are currently drafting the report, which will be presented to ministers at the beginning of next month.
The move follows publication of the study by KPMG which backed government proposals that 80% of council computing should be exposed to CCT (LGC, 15 July).
The councils' report will use evidence gathered by KPMG and other statistical information on local government IT to reach its own conclusion on what level of services should be exposed to competition.
'We are producing the report to counterbalance one view on what the percentage should be,' said Mr Marshall, who is also head of IT at the Corporation of London.
Mr Marshall pointed to concessions on legal and construction-related services to show how the government had altered plans in response to council lobbying. 'There is plenty to play for,' he said.