The Canberra Liberals remain tight-lipped over increasing speculation leader Zed Seselja will contest a seat at the federal election.

Mr Seselja has been ACT Opposition Leader since 2007 and speculation that he may move into federal politics has been rife since he narrowly lost last year's ACT election.

But party insiders are not commenting and Mr Seselja is not giving anything away.

Mr Seselja could run in the lower house or try to unseat Liberal Senator Gary Humphries.

Senator Humphries says that would not stop him running for another term.

"I will be nominating irrespective of what other candidates are put forward," he said.

Liberal nominations close on Monday and a preselection vote will be held later this month.

Senator Humphries says he is the only declared candidate at this point.

"I'm very keen to be both a member of the Senate after this election and hopefully a member of the frontbench in an Abbott Liberal government," he said.