The party's left faction sought to move a previously unheralded motion giving the party's administrative committee the ability to make an exception for preselection candidates who do not meet the party's eligibility criteria in order to run.

The rule change was successful but would not apply to the bitter preselection battles already underway. However a separate motion was passed in order to allow Gail Morgan to continue to run for preselection in the seat of Bean.

Ms Morgan had been found ineligible to run because one of three branch meetings she had attended in the past 12 months was inquorate.

Ms Morgan was not at the conference and was not aware of the wider rule change regarding the administrative committee.

"For affording me the opportunity to nominate for preselection I thank the conference delegates for  acknowledging my more than 20 year commitment to the party, its values and our common goals," Ms Morgan said in a statement.

The chaotic debate around the motions and the walkout reflected heightened tensions in the party around the federal preselection campaigns for the seats of Canberra and Bean. Federal lower house seats in the ACT are considered to be safe for the Labor party and the prospect of two seats without an incumbent has added fuel to the fire between the factions.

Earlier in the day it was announced former senator Katy Gallagher had been preselected unopposed to run to return to her previous position.

The party's affirmative action rules require the party to preselect a woman in at least one of the seats.

Members of the right have described the move by the left of the party as unruly and lawless, and are concerned it sets a precedent for the party's processes to be easily over ruled. The right was blind-sided by the left using their numbers to ensure Ms Morgan, who has long identified with the right faction, to run against the right's endorsed candidate for Bean Senator David Smith.

A senior source in the right said "there was no notice and no discussion of the urgent matter. Control of the room was lost and it's clear that the rules only apply when it's convenient".

It's expected the controversy will be referred to the party's national executive, which has already intervened once in the local preselection process.

It's in the interests of the left faction for a woman to win preselection in the seat of Bean, as the grouping's star candidate in Canberra is St Vincent de Paul Society boss John Falzon.

There were reports earlier in the week that women in the party's right faction had been discouraged from seeking endorsement against Senator Smith. In announcing her resignation on Monday, MP Gai Brodtmann said she hoped a woman would succeed her in the seat.

ACT Labor secretary Matt Byrne, who is also a senior member of the left faction, said he was not involved in the development of the motion. Mr Byrne was elected unopposed for another four-year term as secretary on Saturday.

Taimus Werner-Gibbings, an unaligned candidate in Bean said he was troubled by what happened at the conference.

"I expect the outcome of the last-minute manoeuvres will be a new female candidate in Bean. This is really positive and I'm looking forward to competing against them in the preselection. However, I'm a bit unhappy at the apparent disregard for the conference process used to achieve the outcome and troubled by the precedent," Mr Werner-Gibbings said.

Right-aligned candidate for Canberra Jacob Ingram was also unimpressed by the power plays.

"I'm disappointed that those in power continue to bend rules and centralise their power at the expense of rank and file members. Labor should be about fighting for the shared values of members, not passing last minute dodgy rules changes at conference," Mr Ingram said.