The acting PM told a reporter on Monday that the last time he questioned Mr McGowan about reopening his border, the WA Premier “lost his marbles”.

“Every state and territory, except for WA, has announced plans to reopen their borders. Do you have anything to say to the WA premier?” the reporter asked.

“I did last time, but he lost his marbles with me. So I’ll just let him talk,” Mr Joyce replied.

Mr McGowan has remained steadfast in his protection of WA’s borders, keeping the state firmly closed off from the rest of the country as health restrictions ease.

WA is now the only state or territory that does not have a timeline for the easing of restrictions for fully vaccinated travellers.

“The border will open eventually both internationally and to other states when the time is right in the first half of next year,” Mr McGowan said on Friday.

“We'll set a date in coming months, and then people will have that certainty.”

But Mr Joyce accused the Premier of harming the residents of WA.

“We’re all going to be jumping on planes and flying to other parts of the world,” he said.

“If you want to live and stay in Western Australia forever more, I don’t think that your people will.

“Your people will want to go overseas with us.”

Despite Mr Joyce’s taunt, the WA leader has maintained widespread support from within his state throughout the lockdowns of 2021.

Mr McGowan boasts a staggeringly high approval rating of 89 per cent, with many WA residents praising the Premier for keeping the state mostly Covid-free during throughout Australia’s most recent outbreak.

“We want to get to the other side of this in as safe a way as we can with as little health and economic disruption as possible, and come out of it with Western Australia highly vaccinated and in a very good condition,” Mr McGowan said on Monday.