Gary Humphries will stand again against Zed Seselja for preselection for the Liberals' top Senate spot if the ballot is held again.

Outgoing ACT Opposition Leader Zed Seselja, right, is challenging Gary Humphries for the chance to represent the ACT and the Liberals in the Senate, prompting division in the local party. Photo: Colleen Petch

The ACT Liberal Party is descending into open warfare with members threatening to take action to overturn the preselection process for the party's number one Senate spot.

The party's management committee voted on Wednesday night to proceed with a preselection timetable, despite claims many party members had missed out on qualifying to vote.

Fairfax has been told some party members will now petition for a mass meeting of members, which could overturn the management committee's decision.

Senior Canberra Liberals party member Gary Kent has been threatened with expulsion for speaking out about for the preselection process.

Senior Canberra Liberals party member Gary Kent has been threatened with expulsion for speaking out about for the preselection process. Photo: Elesa Lee

On ABC Radio this morning, Senator Gary Humphries, who is being challenged for his job by ACT Opposition Leader Zed Seselja, said he was not happy with the management committee's decision.

“I'm not okay with it," Senator Humphries said.

Former Canberra Liberals president and Howard government staffer Gary Kent told Fairfax he had been threatened with expulsion from the party for speaking out about the process being undertaken for the February 23 preselection.

“There have been threats to expel me,’’ he said.

Mr Kent said he had written to party president - and former Seselja staffer - Tio Faulkner to express his concerns.

“If a decision is simply to maintain the status quo then a number of people in the division - branch members - will seek to take it further, using the constitutional mechanisms of the constitution,’’ he said.

Some party members are believed to be considering using a petition to trigger a meeting of the Canberra Liberals’ full Divisional Council, which consists of all members, and would have the power to overturn decisions of the management committee.

A meeting of the full Divisional Council could not be held before the preselection ballot but might be able to overturn the result.

Members could also attempt to remove Mr Faulkner from his position at a Divisional Council meeting.

Senator Humphries said he was concerned that the management committee had rejected a proposal to allow existing financial members to qualify for preselection by attending a party meeting.

He said Mr Seselja’s decision to announce he was challenging for the Senate spot on the day nominations closed meant that many party members had been unaware there would be a preselection ballot until it was too late to qualify to vote.

“There have been strong rumours circulating that some people had been asked to attend meetings of the party branches in order to qualify to vote. And it appears that some people had an indication that there would be a challenge before the general membership [were told],’’ he said.

Senator Humphries said Mr Seselja had not publicly announced he was challenging until after nominations had closed on Monday.

"The nominations closed at midday, Zed had a press conference at half past 12," he said.  

“So party members on the whole were unaware that there was going to be a contested preselection. As a result there’s only approximately a third of the party’s membership that’s actually signed up to be preselectors in this preselection. Several hundred party members, many of them very good long-serving loyal party members, are not eligible to take part in this preselection.’’