Labor candidate Taimus Werner-Gibbings was neck and neck with the Greens' Johnathan Davis as counting continued on Sunday, with the winner to take the fifth and final seat in Brindabella.

Mr Werner-Gibbings joined Mr Barr, Yvette Berry, Chris Steel and Murrumbidgee MLA-in-waiting Marisa Paterson on Sunday, as ACT Labor basked in the glow of a sixth consecutive election victory.

A relaxed and jovial Labor leader showed off his football and rugby skills, kicking and tossing the Sherrin with colleagues old and new next to Kambah Adventure Playground.

In a wide-ranging press conference, Mr Barr ruled out handing over the Deputy Chief Minister's role to the Greens, anointed Ms Berry the next Labor leader, took aim at the Liberals' campaign strategy and suggested the defeated Alistair Coe would now seek to prise Zed Seselja's seat in the senate.

While Labor's primary vote was steady across the territory, it enjoyed a huge 7.4 per cent swing in Brindabella - traditionally the Liberals' strongest seat.

Mr Barr said Saturday night's result had validated his comments a fortnight ago that the Canberra Liberals had become complacent in the territory's far south.

"We've had strong swings to us in areas where no one thought that would be the case," Mr Barr said.

"I think we've busted the mythology that Tuggeranong and southern Canberra is somehow a Liberal party stronghold."

In a reverse of what transpired in 2016, Labor lost ground in the Gungahlin-based electorate of Yerrabi, costing first-term MLA Deepak-Raj Gupta his seat in the ACT Legislative Assembly.

Mr Barr partly blamed the result on a suspicion that hundreds of people had accidentally voted for Labour DLP candidates, instead of ACT Labor candidates. The minor party won 4.8 per cent of the vote in Yerrabi, a far better result than it achieved elsewhere.

"One of the factors that has impacted our result a little was the Labour DLP vote, which was quite deceptive, essentially just copying Labor's name. I don't think that's particularly fair but that is the electoral system, it is what it is," he said.

Mr Barr and Ms Berry will now start negotiating a new parliamentary agreement with the Greens, which could have up to six MLAs in the next Assembly after an extremely strong showing on Saturday night.

The Labor leader laid down the ground rules for those talks on Sunday, saying he would not concede the Deputy Chief Minister's position to Shane Rattenbury's team.

He said the number of ministerial portfolios handed to Greens MLAs would be up for debate, but suggested it was unlikely that any of the new representatives would be put in cabinet straight away.

Mr Barr confirmed he would lead Labor for a full term before making a call on his future ahead of the 2024 election. He said Ms Berry would "obviously" be the next ACT Labor leader.

The Chief Minister said Liberals' leader Alistair Coe was "very gracious" when the pair spoke briefly on Saturday night.

Asked to comment on speculation about Mr Coe's future in the wake of the surprisingly heavy defeat, Mr Barr said he believed the 36-year-old would now seek to unseat Zed Seselja in the Senate.

"There is probably a good career for him as ACT Liberal Senator if he is prepared to take it up to Zed Seselja," he said.

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"I'm sure that is in his sights for the future. Zed got there by knocking off Gary Humphries. I'm sure Alistair can get there by knocking off Zed."

Mr Barr said Mr Coe was a decent man who loved his family and the nation's capital, but his conservative views were out of step with mainstream Canberra.

He said his opponent's campaign rhetoric excluded and overlooked Canberrans who didn't fit the "ultra conservative Liberal definition" of a family.