Liberal Senator Zed Seselja is pushing the idea of expanding Tuggeranong to the western side of the Murrumbidgee River and federal Assistant Minister for Infrastructure and Regional Development Jamie Briggs has now gone to the National Capital Authority, asking for a brief on the process for changing the National Capital Plan to allow the expansion.

The move took Mr Corbell by surprise on Thursday. It was "very unusual for the National Capital Authority to talk about initiating changes to the National Capital Plan without informing the ACT government", he said.

"I'm not sure what's going on but it's important that we have collaboration, it's important that we have consultation, and it's important that future planning of the city is done strategically and not in an ad hoc manner," Mr Corbell said.

A spokeswoman for the authority said it would consult with the ACT government, but so far had only been asked for a brief on the planning process. If the federal minister asked the authority to go ahead with an amendment to the National Capital Plan, the board would consider the request and had the power to knock it back, she said.

Even if the National Capital Plan is changed, no suburban development can happen in the area without the ACT government also changing its Territory Plan, so there is no danger Mr Corbell will find a Tuggeranong expansion under his watch without his approval.

But Mr Corbell said a change to the National Capital Plan was nevertheless a very significant step and should not be done in isolation. Changes should only made in coordination with the ACT government and in light of broader development plans across the territory, he said.

"These are decisions that directly affect the roles and responsibilities of the ACT government," he said. "These matters should be considered in a holistic and strategic fashion."