HE HAS been stripped of his party membership, and now Member for Whitsunday Jason Costigan stands to lose almost $25,000 in pay following his expulsion from the LNP.

Mr Costigan will start back at Parliament next week as an Independent member of the cross bench, after the LNP's state executive voted to expel him on Friday following the levelling of a harassment claim against him.

He strenuousuly denies the allegation.

But Mr Costigan stands to lose more than just his party membership and his seat on the LNP back bench, with his spot on Parliament's Innovation, Tourism Development and Environment Committee to be given to another Liberal National MP.

The move means he will likely lose the extra $24,083 per year in pay a committee role attracts, unless a new role is handed to him by the major parties.

It comes as LNP party elder Senator Ian Macdonald yesterday came out in support of Mr Costigan's efforts as an MP.

Senator Macdonald, who is battling to hold on to his Senate post at the looming Federal Election after he lost the coveted No.1 spot on the LNP's ticket to candidate Susan McDonald, said he was unable to comment on the harassment claim levelled against Mr Costigan, as he had been out of the country at the time and was unaware of the details.

But he said Mr Costigan was a good local member.

"I have said on Facebook that he should keep doing the work for his people. I have known Jason for a long time," Senator Macdonald said.

"He is a good local member. He is a hard worker and I know he has won the seat on three occasions when we haven't been able to win it for decades.

"But I can't comment on his expulsion or the reasons for it, because I simply don't know any of the facts."

Mr Costigan was quick to point out Senator Macdonald's support in a post to his Facebook page.

And he took another swipe at Opposition Leader Deb Frecklington, labelling his former boss a "seat warmer".

Mr Costigan also took to Twitter to reveal senior branch members - including the chair, secretary and treasurer of his former Whitsunday LNP state electorate council - had quit over his dumping.