Canberra Liberals health spokesman Jeremy Hanson is the favourite in Monday’s contest for the Opposition leadership, according to online bookmaker Sportsbet.

But the agency says it expects a tight race between Mr Hanson and current deputy Brendan Smyth for the top job.

The two MLAs have been named by the Canberra Liberals as the most likely successors to Leader Zed Seselja, who is resigning to challenge ACT Senator Gary Humphries for his upper house seat.

Sportsbet said on Wednesday the odds of a Hanson win were at $1.80, while Smyth was at $2.10.

Opposition Whip Alistair Coe, who has not been ruled out as a challenger, is viewed as an outside chance at $5.50.

“Both Jeremy Hanson and Brendan Smyth have strong cases and that is reflected in the closeness in the betting,” Sportsbet’s Ben Hawes said.

“However, Mr Hanson is currently the slight favourite given his strong performance in the October election and the fact Mr Smyth has been leader during an election defeat.”

The Canberra Liberals’ eight-strong caucus will gather on Monday, the day before the Assembly sits for the first time this year, to elect a new leader to replace Mr Seselja.

Mr Seselja said on Tuesday he had thoughts on which of his colleagues would make the best successor but he was not going to share those views with the media.

The Opposition Leader said Mr Hanson, Mr Smyth and Mr Coe had been the "standout performers" of the previous term.

Mr Seselja said Mr Smyth and Mr Hanson were "obvious" front runners for the leadership but Mr Coe was not out of the race and was considered a chance for deputy.