Many Liberal members in the party's southern electorate branch in Tuggeranong will now be denied the right to vote despite thinking they had fulfilled their eligibility criteria.

Doubts are also being raised about the ability to vote of members of a Weston Creek sub-branch, who also attended meetings in good faith.

The latest development means that voting eligibility problems have emerged in five of the eight Canberra Liberals' internal groups.

To be eligible to vote, a financial member must have attended a properly constituted party meeting within six months of the preselection poll but the party has been brawling bitterly since former local leader Zed Seselja declared he was challenging incumbent senator Gary Humphries.

The timing of Mr Seselja's declaration, half an hour after the rolls closed, sparked fury among some members of the party who said they had been locked out of the process.

But divisional president Tio Faulkner and his former boss, Mr Seselja, have consistently argued that the process has been undertaken within the party's constitution.

Mr Faulkner said on Monday that ''there is simply no way to bend the rules for people who, unfortunately, find out they cannot vote in the preselection''.

''I really have sympathy for all members who find out they are not eligible to be a preselector. It is disappointing for them, for me and for the party. However, the rules have been and can only be applied fairly across the board - we cannot bend and change after the event,'' Mr Faulkner said.

The problems with the northern branch emerged on February 7 and at least one long-term party member, who contributed financially to the Liberals' 2012 election effort, has quit the party in protest.

Meetings held in late January by the party's Women's Council and the Young Liberals, just days before Mr Seselja declared his hand, have attracted complaints that they may not have been constituted properly to give participants voting rights.

The Canberra Times understands that the party's internal electoral returning officer, Martin Dunn, himself a former Senate hopeful, is looking at the problems that have been raised with the southern branch, Weston Creek, with the Women's Council and Young Liberals. Mr Dunn did not respond on Monday to a series of questions.

Former party president Gary Kent, who has been mobilising support to have party officials abandon the preselection and start again, confirmed that he had approached Mr Dunn asking him to investigate.

''I have approached the returning officer raising concerns about the status of a number of branches for qualifying purposes for preselection,'' Mr Kent said.

''It would appear that several other branch meetings were unconstitutional and if so that will mean even more members of the Canberra Liberals will be unable to vote at the preselection on Saturday.

''It would appear there has been a catastrophic failure in the management of the division in terms of oversighting the activities of those branches.'' The former federal parliamentary staffer renewed his call for the party to begin the process again.

''I am concerned that there are a range of problems with various meetings of those branches which would cast grave doubts on their validity to qualify members who attended them to vote at preselection,'' Mr Kent said.

''Those issues relate primarily to lack of notice to branch members about the meetings and lack of quorum.''