Members of the public who suspect misbehaviour by ACT's politicians could soon have their claims investigated by a standards commissioner.

Greens Minister Shane Rattenbury will move two motions in the Legislative Assembly this week asking MLAs to formally agree to adhere to an updated code of conduct, and to set up the Commissioner for Standards.

Mr Rattenbury says the measures will boost expectations of behaviour for the territory's politicians.

"Members of the public or other members of the Assembly could lodge a complaint with the Speaker," he said.

"The Speaker makes an initial assessment of whether there's some level of credibility to the complaint or whether it's vexatious.

"If it proceeds past that first threshold, then the Commissioner for Standards would be asked to investigate the matter.

If the Commissioner uncovers a breach, the Assembly would determine an appropriate punishment.

Mr Rattenbury says he expects both resolutions to be approved.

"In having an independent commissioner for standards there can be a confidence that there is a level of higher standard of external oversight but without the potential perception of partisanship."