The work seizes the Dutton child care letter in a new impetus for referral to the High Court

Peter Dutton

New evidence shows that it has become "completely untenable" for Peter Dutton to avoid the High Court over his personal involvement in two publicly funded child care centers, says Labor Labor.

Opposition member Jim Chalmers says a letter, which has come to light in recent days, casts further doubt about the Interior Minister's eligibility to remain in parliament.

"It has become completely untenable for Scott Morrison not to refer Peter Dutton to the High Court," Chalmers told Sky News on Thursday.

The letter shows that one of the Brisbane child care centers held by Mr. Dutton in trust had a financing agreement with the State to allow the hiring of a teacher with special needs.

Late last month, a Labor effort in parliament to force Mr. Dutton to the Supreme Court was lost by a single vote.

The opposition believes it has the numbers of the lower house to try again when the parliament returns next week, with Labor MP Emma Husar returning after a personal permit.

"Scott Morrison must exercise some leadership and refer him to the High Court." There are so many unanswered questions about Peter Dutton's eligibility to sit down, "said Chalmers.

"When parliament is on the razor's edge, as it is, that questions all kinds of decisions that Morrison's cabinet will make."

Labor Parliamentarian Mark Dreyfus (Archive)

AAP

Shadow Attorney General Mark Dreyfus said the minister was "most likely" ineligible to sit in parliament, particularly since the attorney general recently said there were doubts about his position.

Dreyfus said the minister's eligibility could challenge thousands of decisions he has made as minister of immigration and home affairs.

"It is also an important issue because this is a government that is pending a thread of control from the House of Representatives," he told reporters in Melbourne.

"It is extremely significant that one of its oldest members, Peter Dutton, is probably not eligible to sit in parliament."

The Constitution prohibits any person who has a direct or indirect financial interest in Commonwealth assets from parliament, as it may create a conflict of interest.