The federal court has rejected the claim Peter Dutton’s ministerial decisions in the 45th parliament can be challenged based on his alleged constitutional ineligibility, dismissing the idea as “purely hypothetical”.

On Wednesday Justice Jennifer Davies upheld a challenge against a decision of the home affairs minister to cancel a humanitarian visa because he did not separately consider Australia’s non-refoulement obligations, but rejected the suggestion his former interests in childcare centres could threaten the validity of his decisions.

Dutton says AFP must take extra steps before launching raids on the media Read more

The judgment appears to close off an avenue pursued by Labor to question the validity of past ministerial decisions where the alleged constitutional ineligibility is yet to be proven, potentially saving hundreds of Dutton’s migration decisions from challenge.

In the last parliament, Dutton was revealed to have interests in childcare centres that received federal subsidies, arguably in breach of the ban on indirect pecuniary interests in an agreement with the commonwealth.

Dutton received advice from the solicitor general that he was eligible to sit in parliament but ditched the interests before the 2019 election and never came under direct constitutional challenge.

But in a federal court hearing just a day before the election the applicant known as FQM18 claimed that Dutton’s decision to revoke a global special humanitarian visa was invalid in part because “he was not constitutionally permitted to act as a minister”.

Section 64 of the constitution says no minister of state shall hold office for a longer period than three months unless he is or becomes a senator or a member of the House of Representatives.

The applicant sought a stay until the high court could consider if Dutton was eligible.

Justice Davies noted that when Dutton made his decision parliament had been prorogued and his eligibility had not been referred to the court of disputed returns, concluding it was “not appropriate to grant a potentially indefinite stay on the basis of a purely hypothetical sequence of events”.

“A fundamental difficulty with the applicant’s argument is that the relief sought is as against the minister in his ministerial capacity, rather than as against the minister personally,” she said.

Sign up to receive the top stories from Guardian Australia every morning

“Even if a referral of the minister to the court of disputed returns resulted in the removal of the minister from parliament, it is far from clear that the minister’s impugned decision would be invalidated insofar as the decision was made in the apparent execution of his office.”

Justice Davies cited a majority of the high court in Cassell v The Queen which appeared to support “the principle of the common law that where an office exists but the title to it of a particular person is defective the ‘acts of a de facto public officer done in apparent execution of his office cannot be challenged on the ground that he has no title to the office’.”

Nevertheless, Justice Davies upheld the appeal on the basis Dutton had conflated the criteria for the grant of a protection visa under the Migration Act with Australia’s non-refoulement obligations under international law.