Professor John Uhr said he was cautious of models similar to the Independent Commission Against Corruption where a powerful, broad-based authority can scrutinise any area of government.

"The risk of an ICAC-type body is that we deflect criticism of a minister to supposedly an expert body," he said.

"The cost of everybody now facing not just ministers, not just the Legislative Assembly, the Canberra Times, not just the auditor-general but the new body, is it adds to the stress within government.

"Maybe that's an appropriate stress or maybe in some cases it's a step too far."

Professor Uhr, from the School of Politics and International Relations, said a lot could be gained by having a properly appointed ICAC, but it had to be careful not to gazump the role of the Legislative Assembly in holding ministers and public servants to account.

The Labor government promised last Saturday to create an Integrity Commissioner if re-elected, about a month after the Canberra Liberals shifted from their earlier stance and promised to establish an ICAC. The Greens had led the way, promising an independent Integrity Commission at their campaign launch in July.

Professor Uhr saw no substantial difference between the integrity bodies proposed by the three parties.

Liberals leader Jeremy Hanson has described Labor's plan as a "watered-down" version of his own, while the Greens have congratulated the two major parties for bowing to community pressure and agreeing to "our proposal".

Correction: An earlier version of this article incorrectly referred to Professor Uhr as being from the Crawford School of Public Policy, which he left in 2011.