Former One Nation senator Brian Burston says he is "very comfortable" joining Clive Palmer's new political party, despite his new leader's chequered history.
Senator Burston officially quit Pauline Hanson's party on Monday and immediately announced he would be part of Mr Palmer's rebadged United Australia Party.
"We will unite Australia and we will bring integrity back into the Senate," Senator Burston told reporters in Canberra on Monday.
At a chaotic press conference at Parliament House, Labor MP Cathy O'Toole heckled Mr Palmer about former Queensland Nickel workers who say he owes them money.
"I don't owe anyone anything in north Queensland," Mr Palmer said.
Mr Palmer blamed the liquidators for any missing money, and said he planned to reopen his Townsville nickel refinery.
He is also facing criminal charges in Queensland, which he did not comment on.
Senator Burston said he was "very comfortable" standing next to Mr Palmer, even with his former workers complaining about not being paid.
"That issue is before the courts and I am not in a position to comment and I won't comment," Senator Burston said.
Mr Palmer later confirmed he was interested in running for the north Queensland seat of Herbert, which Ms O'Toole won in 2016.
He previously held the seat of Fairfax from 2013 to 2016.
Prime Minister Malcolm Turnbull did not comment on Senator Burston's defection.
"As far as Mr Palmer is concerned, I guess all I can say is we have seen that film before," Mr Turnbull told reporters.
