The PUP leader accused Senator Lambie of being a "drama queen", and dared her to challenge him for the leadership if she is truly unhappy with the direction the party is taking.

His statement marked a new low in their relationship after Ms Lambie publicly questioned the performance of Mr Palmer and her Senate colleagues Glen Lazarus and Dio Wang, advising them to find a "bloody better plan of attack than what they've been using".

Speculation was rife on Thursday that Mr Palmer's provocative statements would force Senator Lambie to choose between the party and her controversial chief of staff.

But she instead welcomed the move to expel Mr Messenger and made the strange claim that she wanted a "non-political office" behind her.

"I'm very happy with my electoral team, including my chief of staff, Mr Messenger," she said.

"They are 100 per cent loyal to me, and together we are fighting hard for members of our Defence Force, War Veterans and ordinary Tasmanians.

"I've requested that all my staff not be members of any political party. I want a non-political office and Mr Palmer's confirmation that Mr Messenger is no longer a member of the Palmer United Party saves him the trouble of resigning."

Mr Palmer told Fairfax Media he did not expect Senator Lambie to defect from PUP. "There's no suggestion she will leave the party," he said.

In his earlier statement, he said: "Everything Senator Lambie says is really coming from her chief of staff. Senator Lambie is simply Rob Messenger's mouthpiece."

He described Mr Messenger, a former Queensland National Party MP, as having no experience in federal politics.

Mr Messenger resigned from the Liberal National Party in 2010 to become an independent but landed in hot water over a perceived anti-Muslim bias. In a letter to the editor of a regional Queensland newspaper, Mr Messenger claimed there were Islamic terrorists living in our midst "sustained by our welfare payments", and compared society's tolerance to the Germans failing to stop the growth of the Nazi party in the 1930s.

Mr Messenger has issued a string of statements on behalf of Senator Lambie calling for wearing of the burqa to be banned in public and railing against Sharia law.

Mr Palmer said: "Last night our executive met and we have agreed to expel Rob Messenger from the party on the grounds of making false and misleading statement about our senators," he said.

Senator Lambie's vote in the Senate is one of a four-person bloc comprising Mr Palmer's PUP senators and the Motoring Enthusiast senator Ricky Muir.

If she were to become an independent, it would cause new headaches for the government, which would have to negotiate with Senator Lambie and other crossbenchers individually, instead of as a bloc, in trying to pass its legislation.

It's understood Liberal Democrat senator David Leyonhjelm and Family First senator Bob Day are willing to open talks with Senator Lambie about forming their own three-person swing bloc if she does decide to abandon Palmer United.

Mr Palmer has no technical way of stopping Senator Lambie from continuing to hire Mr Messenger and remaining within the party, unless he expels her and risks losing one of his powerful votes in the Senate.

Tensions within the party have been evident for some months but have heated up most recently over the issue of the government's pay offer to the military.

While the PUP is united in its opposition to the government's offer, Senator Lambie's colleagues have rejected her threat to boycott government legislation and attempt to hijack Remembrance Day ceremonies.

The matter reached a head when the Tasmanian senator warned her colleagues on Wednesday to get into line with her views or face the prospect of the party splitting.

"If the party is going to survive, then they better come up with a bloody better plan of attack than what they've been using," Senator Lambie warned and noted support for the party was slipping in the polls.

On Thursday she said: "Mr Palmer's personal criticism of Mr Messenger is disappointing. Mr Messenger and I have worked well together after Mr Palmer gave us the job before the last federal election to create a veterans' affairs and defence policy.

"Because both Mr Messenger and I served as members of the Australian Defence forces, we've been able to create a policy that treated our Diggers and their families fairly."

Mr Palmer told Fairfax Media that its report in September, which triggered a bizarre response from Mr Messenger to journalists, was one example of Mr Messenger's misconduct.

In that incident, Mr Palmer was overhead by sources questioning Senator Lambie's intelligence.

When asked for a comment, Mr Messenger emailed the entire press gallery a response and claimed Mr Palmer had criticised Senator Wang's intelligence instead.

Mr Palmer said that was obviously not true as he has a high regard for Senator Wang's intelligence.