"He is a member of the parliament, he is a backbencher now, and he is a former prime minister. I'm not going to be giving him advice as to what he should or should not say."

In a dig at Mr Abbott, Mr Morrison said Immigration Minister Peter Dutton, Justice Minister Michael Keenan and their staff would not have entered into the arrangement with Senator Leyonhjelm without the knowledge of the Prime Minister or his office.

"They were doing their jobs in accordance with the practices which were long established," Mr Morrison told radio 2GB.

"Every time I was negotiating a bill through the Upper House I always kept people closely informed and knew they were aware."

The issue exploded last week when Prime Minister Malcolm Turnbull effectively branded Mr Abbott a liar for contending neither he nor his office knew anything of the supposed deal.

"Wrong, wrong. A staffer in a minister's office, no deals from me. No deals from my office. No deal," Mr Abbott told the ABC's 7.30 on Wednesday last week.

This infuriated Mr Keenan who went to Mr Turnbull with an email trail showing Mr Abbott or his office was clearly aware of the arrangement.

Mr Dutton then went to see Mr Abbott on Thursday suggesting he release a statement correcting the record because the government was not going to lie to cover him during question time. Mr Abbott declined so Mr Turnbull let fly during question time.


"I have made inquiries of my ministers and can say to the House as a result of those inquiries I'm satisfied that the Minister for Justice acted in the full knowledge of the Prime Minister's Office at that time," Mr Turnbull said.

An email released by Senator Leyonhjelm last week showed the government was prepared to lift the import ban on the seven-shot Adler shotgun after 12 months "in return" for his vote on a immigration bill.

As well as denying any knowledge of the bill, Mr Abbott has said he never had any intention of lifting the ban.

When the ban was about to end this year, Mr Turnbull renewed it and Mr Keenan told Senator Leyonhjelm that the government never had any intention of lifting it.