He will advocate this scheme with the Abbott government as a way of revitalising the town centre.

The radical plan could be opposed on environmental grounds due to the likely need to build another bridge across the river corridor. However Senator Seselja said proposed suburbs to the north of Tharwa were part of original zoning under the national capital plan, before self-government.

"The Tuggeranong town centre is struggling somewhat and unless there are some changes in planning and policy it will continue to struggle,'' he said.

"The biggest thing that affects Tuggeranong town centre is the decision taken before self-government not to complete the Tuggeranong Valley over the river.

"That has skewed the geography of the town centre - the town centre is not in the centre of the town, it's on the western edge.

''We should have a conversation about actually opening that up.

"I'm an advocate for the original plan which did involve some development over the other side of the river.''

Senator Seselja said the decision by the then federal minister Tom Uren to halt the proposed development had had an ongoing impact.

''As a result of that decision we've seen more southside development going over the border,'' he said. "Southsiders have tended to stick on the south side, but it means going over the border if you want a new home because Tuggeranong ran out of space.''

Senator Seselja said any proposal to build west of the river would need federal government approval.

''It's something that I would advocate for with the NCA, to actually have another look at it,'' he said.

''Obviously all of these things have to take into account the environment and a range of things, but there's no practical reason why you couldn't see reasonable development.

''I think the ACT government should look at it but it would need to be a collaborative Commonwealth-ACT approach.''

Tuggeranong needed better facilities for its residents, such as a tertiary education institution. He hopes the ACT government will soon announce plans to build a CIT campus there.

''It would certainly be a positive but hopefully it won't be a Mickey Mouse approach, I hope there will be a genuine campus in Tuggeranong rather just an outpost,'' he said.

He also hopes some of the recently announced $85 million to clean up Canberra's waterways will be spent on helping reduce pollution in Lake Tuggeranong, such as by building wetlands to filter the water going into the lake. Amid persistent rumours about the future of the huge Social Services Department, Senator Seselja says he believes the public servants will stay. ''I'd obviously like to see DSS stay there. There was talk under the former government of moving DSS out of Tuggeranong and I think that would be a significant blow,'' he says.

He does not have a definite assurance about the DSS.

''I'm very hopeful that it will stay in Tuggeranong.''

ACT Education and Training Minister Joy Burch said no decision had been made on whether a future CIT campus for Tuggeranong would be a greenfields site or go in the main street.

''I've not been shy about my clear determination and commitment to have a significant presence of CIT in Tuggeranong,'' she said.

Figures supplied by her office show almost 3000 CIT students live in Tuggeranong but just over 1000 in Woden. In addition, the campus in Woden is ageing.

''If you look at where the students that are going to Woden come from, predominantly they come from Tuggeranong,'' Ms Burch said.

''The campus at Woden is an ageing, rambling precinct - that's not news to anybody.

''So it all stacks up, and it is very logical to have a serious investment of CIT in Tuggeranong.''