Joyce said it was “bitterly disappointing” Turnbull had been lobbying his successor to refer cabinet minister Peter Dutton to the High Court.

“It seems like he has an active campaign to try and remove us as the government. That is bitterly disappointing,” he told the Australian Financial Review.

Turnbull, who is holidaying in the US after stepping down as prime minister last month, has been lobbying his successor Scott Morrison to clarify Dutton’s constitutional eligibility to remain in parliament.

“I’ll obviously make the decisions in relation to our government on what I believe is in the national interest and based on the most recent and most timely information that I have available to me,” Morrison told reporters today.

“I think people have had enough of the lawyer’s picnics on these sort of issues and they want to focus completely and totally on what the nation needs here and now.”

Turnbull says Dutton’s constitutional position needs to be clarified, comparing it to the case of former deputy prime minister Barnaby Joyce.

“The point I have made to @ScottMorrisonMP and other colleagues is that given the uncertainty around Peter Dutton’s eligibility, acknowledged by the Solicitor General, he should be referred to the High Court, as Barnaby was, to clarify the matter,” he tweeted.

Dutton, who did not achieve his ambition to replace Turnbull in last month’s Liberal leadership stoush, said his former boss should “enjoy his retirement”.

“Mr Turnbull never raised once with me any issue around section 44,” the minister told 2GB radio.

“His staff never raised it with my office, he never asked me for the legal advice that I had that showed I had no problem at all.”

Former Liberal deputy leader Julie Bishop said all members of parliament had a “personal responsibility” to ensure they were eligible to sit in parliament.

She said Dutton had already stated there was no issue about his eligibility and it was up to others to “demonstrate that statement is not correct”.

Dutton’s family has a financial interest in two Brisbane child care centres which receive Commonwealth funding.

At issue is whether this makes him ineligible to sit in parliament under section 44 of the constitution which disqualifies anyone who has a “direct or indirect pecuniary interest” in any agreement with the Commonwealth.

At the height of the Liberal leadership crisis, Solicitor General Stephen Donaghue advised he could not categorically determine Dutton’s status and only the High Court could.

However, Donaghue found on balance Dutton was “not incapable” of sitting as an MP.

– AAP