In the latest chapter in a long-running saga, the nation's highest court has agreed to hear an application from ex-Liberal member Matthew Camenzuli at 4pm on Friday.

The application has been fast-tracked after the NSW Court of Appeal earlier this week dismissed Mr Camenzuli's attempt to have the federal executive's intervention into local preselections ruled invalid.

Mr Camenzuli has now been expelled from the party.

The High Court challenge presents a fresh headache for Mr Morrison as he weighs up when to send Australians to the polls.

Media reports suggested Mr Morrison was set to fire the starter's gun on the campaign on Friday.

But calling the election before the court case is resolved means the Prime Minister would be starting the campaign with at least some doubt hanging over a swag of candidates.

The federal Liberal executive launched two temporary interventions into the NSW division after it failed to install candidates amid bitter internal divisions.

The first was to protect three sittings MPs from preselection challenges, with the second installing hand-picked candidates in a further nine seats - including Eden-Monaro.

The NSW Court of Appeal tossed out Mr Camenzuli's case on the grounds it couldn't rule on an internal party dispute.

But Justice John Basten indicated that the intervention was valid given the broad powers under the federal executive's constitution.

Mr Morrison was coy about whether he planned to call the election on Friday.

"The election will be called when I'm in a position to go to the Governor-General," he said.

The Prime Minister has endured a torrid run up to the formal campaign, including vicious attacks on his character from fellow Liberals and a verbal pray from a pensioner at a Newcastle pub.

Mr Morrison brushed off the confrontation on Wednesday night, insisting he was keen to understand the man's concerns.

"More broadly, it was a very welcome reception, of course, there was one gentleman who was there last night who was very upset about what was a very complicated issue," he said.

As Mr Morrison campaigned in the marginal Labor-held seat of Dobell on the NSW Central Coast, Labor leader Anthony Albanese wrapped up a tour of WA before flying to Adelaide, where the opposition is hoping to snatch the seat of Boothby.

Neither leader will be able to count on support from the United Australia Party, with its billionaire president Clive Palmer declaring it would preference the Greens over the two major parties.

"That's my personal perspective, because they [the Greens] haven't been in government and haven't been responsible for this debt," Mr Palmer told the National Press Club on Thursday.

Meanwhile, Defence Minister Peter Dutton will on Friday join Ukraine's ambassador to Australia, Vasyl Myroshnychenko, for an announcement on military assistance for Ukraine.