Former prime minister Malcolm Turnbull has resurfaced in New York City, and he's sharing his ideas one what his successor Scott Morrison should do about Peter Dutton.

Mr. Turnbull and wife Lucy went to their Manhattan apartment for a few weeks after the gruesome leadership spill.  In between dodging paparazzi and going to the grocery store, Malcolm hit Twitter to recommend that PM Scott Morrison refer the Home Affairs minister to the High Court:  "..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."

Labor had raised questioned about whether Dutton had properly declared a family business interest in childcare centers and opted out of relevant cabinet deliberations.  He claims he had "never taken a dollar of distribution from that enterprise" and says it was his "wife's business".  This is despite also being a beneficiary of a trust that operates the centers.  Section 44(5) of the constitution bans politicians benefiting financially from dealing with the Commonwealth.

Former foreign minister Julie Bishop raised the stakes further, saying "of course we want clarity around the standing of all the members of Parliament" - but leaving open the question of how she'd vote if a referral were to come up in Parliament again. 

"If there's a vote on the matter well I'll make my mind up at that time, but of course we want clarity around the standing of all the members of parliament," said Ms. Bishop.

PM Morrison is in no hurry to refer Dutton:  "I think people have had enough of the lawyers' picnics on these sort of issues," he said.