The fate of the Liberal senator and challenger David Pocock has held the attention of Canberrans for weeks. It will be decided as preferences are distributed in "a matter of seconds" shortly after 10am by the electoral commission's EasyCount computer program.

The defeat of Senator Seselja will spell the end of federal Liberal representation in the ACT and open up a power vacuum within the Canberra Liberals. The senator has had an iron grip of power on the local branches of the Liberal party for the past decade. The 15-person management committee is said to be dominated by Senator Seselja loyalists. The rank-and-file membership is also skewed conservative.

The Canberra Liberals have had several weeks to accept that it was facing a likely loss of its only federal representation and potentially many elections in the political wilderness.

There have been calls from prominent party figures for the organisation to shift back to the centre and some moderates have expressed hope that the loss of Senator Seselja will prompt members to support changes, once the result has been confirmed.

Most notably, former Liberal chief ministers Kate Carnell and Gary Humphries blamed Senator Seselja's conservative views, particularly his stance against the territory's right to legislate on voluntary assisted dying, for the loss.

Labor Finance Minister Katy Gallagher is guaranteed to retain the first of the two ACT Senate seats when distribution of preferences is determined by the AEC.

Mr Pocock is expected to overtake Senator Seselja on preferences to claim the second seat. Three major election analysts all declared victory for Mr Pocock following the May election.

Senator Seselja has refused to conceded the race, which gripped the territory and upset the dominance of the two major parties to represent the capital at the federal level.

Around 10am an official from the electoral commission will press the enter key to run the EasyCount program to distribute preferences and almost instantly reveal who won and exactly how close the race really was.

The commission finalised scrutiny of the ACT Senate vote and preference data entry on Monday. That data will be fed through what it calls a "highly complex algorithmic process". The data will published after the return of the writs so researchers can reproduce the result.

The Liberal Party received just 74 per cent of a provisional quota of first preferences. It was a significant swing against the party, which almost secured a full quota at the previous election.

Mr Pocock picked up around 64 per cent of a quota, but the redistributed preferences from eliminated candidates, including the Greens candidate Dr Tjanara Goreng Goreng and independent Professor Kim Rubenstein, are expected to favour the former Wallaby captain.

"Pocock will win," ABC election analyst Antony Green declared last week.

Independent election analysts Kevin Bonham and William Bowe also had no hesitation in declaring that Mr Pocock would win and become the first independent ACT senator.

While both candidates have remained relatively tight-lipped on the result, Mr Pocock last week expressed confident he would win.

"Based on the numbers, it's looking very positive," he said.

Mr Seselja has avoided speaking with media but issued a brief statement through social media the day after the election. He said the results were disappointing for the Liberal Party across the nation. Commenting on his own chances, Senator Seselja indicated he was pinning his hopes on pre-poll and postal ballots.

The Canberra Liberals have all but conceded Senator Seselja will lose his seat in what is being described as a "bitter blow" for the local branch on top of the Coalition's federal election drubbing.

"While counting of the ACT Senate vote continues at something of a glacial pace, it is clear that Zed's path to retaining the Senate seat is very narrow and Pocock remains the front runner to gain the seat on preferences," ACT party president John Cziesla said in an email to members seen by The Canberra Times last month.

The ACT is used to the result being clear early on, but the official counting for the Senate seats usually takes some time.

Counting the votes is complicated. There are 314,000 Senate votes in the ACT, for example, and if you then look at conceivable preferences from one to six, the number of combinations is huge.

On top of that, there are levels of security - computer scanning of ballot papers is checked by human beings.

"Right, not rushed," is the mantra, according to Electoral Commissioner Tom Rogers. "It's a key principle for us and despite an understandable external desire for things to be wrapped up quickly, it is a principle that maintains the strength of Australian elections.

"We will deliver legal, transparent and trusted results by the legislated deadline."

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