Former Defence Minister Christopher Pyne is facing a Senate inquiry into his new consultancy gig, with his nemesis Cory Bernardi tipped to back the probe.

Centre Alliance Senator Rex Patrick told The New Daily he believed he had the backing of Labor, the Greens and the Australian Conservatives leader.

“I think I will get the numbers. Jacqui (Lambie) has indicated to me that she will support it,” he said.

“Cory will support it.”

The enmity between Mr Pyne and Senator Bernardi runs deep. Malcolm Turnbull once removed Senator Bernardi from the frontbench for undermining Mr Pyne.

The crossbench senator wants Prime Minister Scott Morrison to enforce the federal ministerial standards that require ministers do not lobby, advocate for or have business meetings with the government or MPs on “any matters on which they have had official dealings” in the past 18 months.

This looks like a nice start to your Senate inquiry submission which will, no doubt, compliment your Committee appearance. You and @EY_Australia will also be able to provide evidence detailing the “rigorous processes and procedures” you referred to in your statement #auspol https://t.co/OdEgf7UGGV

— Rex Patrick (@MrRexPatrick) June 30, 2019

Senator Patrick said Mr Pyne’s decision to take a job helping consulting firm EY’s defence-related business “just doesn’t pass the pub test”.

“Neither Mr Pyne nor EY have been able to offer any convincing explanation as to how Mr Pyne’s new job can properly be reconciled with the prime minister’s ministerial standards concerning post-ministerial employment.

“Mr Pyne cannot un-know what he knows from nearly three years’ service at the top of the Defence portfolio.

“His acceptance of his new job with EY is unquestionably a breach of the spirit, and indeed the letter, of the prime minister’s standards. The question is now that of what the prime minister is going to do about it.”

If Mr Morrison chooses not to enforce the standards, Senator Patrick is proposing a Senate inquiry.

“To help focus the prime minister’s mind and support his personal role in ensuring integrity within government, it would be timely for a Senate Committee to inquire into the compliance of former ministers with Mr Morrison’s ministerial standards,” Senator Patrick said.

“An inquiry by the Senate Finance and Public Administration References Committee would be able to seek all relevant information from Mr Pyne, EY, the Department of Defence, the Department of the Prime Minister and Cabinet, and from the prime minister himself. If necessary, such an inquiry can employ the full powers of Senate Committees to obtain documents and information.”

Labor Senator Penny Wong called on Mr Morrison to enforce the ministerial code of conduct.

“If Mr Pyne is being employed by EY to expand their defence business, it certainly does not suggest that he’s only using knowledge that the general public have,” she told ABC Radio on Monday.

“I would suggest it looks like he’s been appointed because of his knowledge, and there are clear provisions in the code against that.”

Labor is also considering Centre Alliance Senator Patrick’s call for an inquiry into the appointment.

“Ultimately the buck stops with the prime minister. Mr Morrison has to enforce his standards. The ministerial standards are his standards,” Senator Wong said.

In a statement Mr Pyne said: “I know my responsibilities under the code and I will abide by them.”

“I have not taken personal advantage of information I received as a minister in the defence portfolio that is not otherwise publicly available,” he said.

“Having that knowledge does not breach the code.

“I intend to ensure that anyone I provide advice to has rigorous processes and procedures in place to ensure I am not put in a position where the ministerial code of conduct might be breached.”

Ernst & Young said Mr Pyne was mindful of his responsibilities in meeting the guidelines.

“Mr Pyne has made clear that he is totally aware of his obligations under the ministerial code of conduct and is committed to adhering to them,” the statement said.