Prime Minister Scott Morrison has denied pulling out of the Clive Palmer border challenge because he feared a backlash from West Australian voters.
The matter will return to the Federal Court on Friday for a case management hearing sought by the WA government, which argues Mr Palmer's case against the border closures should be vacated and a new trial convened.
It comes after Mr Morrison wrote to WA Premier Mark McGowan saying the Commonwealth would no longer support the challenge.
Federal Attorney-General Christian Porter is one of several WA Liberal MPs who risked an electoral backlash given voters' overwhelming support for border closures.
But the prime minster says that wasn't why the Commonwealth withdrew its involvement.
"I don't think that's what people should believe either because that's not how it played out," Mr Morrison told 6PR radio on Thursday.
"What I've learned ... as I've sought to manage this crisis from a national perspective is you've got to move as circumstances change.
"I didn't want there to be any anxiety in Western Australia and I didn't want that juiced up by anyone seeking to create any panic or anxiety. I think that would be very harmful."
Mr Porter this week conceded the Morrison government's intervention in the matter was degrading its ability to work cooperatively with WA.
WA's Labor government had already begun campaigning against the intervention of the "Liberal Party" in the matter.
The prime minister said the Commonwealth was now "out of the case" but would make representations in Friday's hearing.
"I've got no beef with the WA government on this ... I'd prefer it had never arisen and I'm pleased we're out of it," he said.
Mr McGowan earlier said the federal government should withdraw all of its evidence and assist WA in seeking a new trial.
"This is a big issue for West Australians," he said.
"We're doing our best to save lives and also get our economy up and running within our hard borders."
Mr Palmer, who was denied an exemption to WA's hard border closures, is challenging the restrictions on the basis they are unconstitutional.
A ruling had been expected in the High Court in October after a four-day hearing concluded in the Federal Court last week.
That is almost certain to be delayed if a new trial of issues is ordered.
The legal battle has fuelled animosity between Mr McGowan and Mr Palmer, who the WA premier has labelled "Australia's greatest egomaniac".
Mr McGowan has linked the billionaire's entry bid to his purchase of almost 33 million doses of hydroxychloroquine, an anti-malarial drug touted by US President Donald Trump, which has since been found to be ineffective at treating COVID-19.
In a statement, Mr Palmer said he was strongly committed to West Australians' wellbeing.
"I wish the premier and his family no ill will, and trust they are in good health," he said.
"The WA border matter is before the Federal Court and is not of a political nature, it is a legal issue about the powers of government."
Australian Associated Press