A lawyer in Papua New Guinea says the country's highest court is to review the Australian assistance mission now under way.
This comes as the former solicitor-general, Zachary Gelu, appeals for re-instatement following his suspension for misconduct.
Mr Gelu has recently returned to the public service but his position had already been advertised.
He says an Australian shouldn't be appointed to the role as part of the Enhanced Co-operation Programme and the Australian assistance mission is unconstitutional.
His lawyer, Victor Habuka, says his client's goal is to stop the Enhanced Co-operation Programme or E-C-P, so he can return to office.
"The ECP programme is now the subject of a Supreme Court review; the documents have already been filed and the Supreme Court is in the process of determining whether or not that treaty is constitutional. The ECP agreement cannot take place because there's already a solicitor-general in place, and that's my client, that's the way we're arguing it."
Mr Habuka says his client has got a court to issue a restraining order stopping the attorney-general from appointing a solicitor-general.
Mr Gelu is to apply for a summary judgment next week in a bid to resolve the issue, without a full trial.