Jacqui Lambie has told her Senate replacement Steve Martin he is being dumped from her party for breaching the values of "mateship, respect and integrity".
The Tasmanian senator-elect said he had Ms Lambie's blessing to take her seat and he was surprised to learn via the ABC that she had expelled him.
Alderman Martin said he had been out to dinner with his family and not heard about the decision by the Jacqui Lambie Network (JLN).
The ABC had to read Ms Lambie's media release to the senator elect on the telephone.
"From the outset Jacqui gave me her blessing to take the seat and I've been consistent with that approach and [was] working towards gaining clarification with regards to in the office of profit under the crown which was a landmark case," he said.
"I spoke with Jacqui mid-afternoon where she asked me to stand aside and I advised her that I was continuing on as I have been, and being duly elected this Friday and after that there's been no other contact."
The rift comes after Alderman Martin, the current Mayor of Devonport and a member of the Jacqui Lambie Network, was ruled as eligible to take up the Senate spot vacated by Ms Lambie, who resigned last year because she was a dual citizen.
Ms Lambie told the media earlier this week she hoped Alderman Martin would resign the Senate seat, creating a casual vacancy she could take up.
However, Alderman Martin said he would not do that, but he would serve as a (JLN) senator.
Late on Wednesday, the JLN released the text of a letter from Ms Lambie to Alderman Martin.
"Dear Senator Elect Martin, I congratulate you on your recent win in the High Court. It sets a new legal precedent allowing local government representatives to run for federal office," the letter began.
"The Jacqui Lambie Network prides itself on mateship, respect and integrity. I do not believe that your actions have been in keeping with these values, which I and the other JLN members hold dear.
"I don't feel you've been honest or upfront with me since my resignation."
Ms Lambie wrote that Alderman Martin had given a "commitment" to retain JLN staff.
"Today you announced they are all to be terminated," she wrote.
"This, coupled with your lack of commitment to the Network since the last election shows us that you are not interested in following our values."
Ms Lambie said Alderman Martin had made public statements to the media, "purporting to be from the party".
"This was done without getting the authority of the convenor to make any such statements."
She wrote it was "my duty to inform you, that the management committee of the Jacqui Lambie Network has moved to expel you from the party".