However, Senator Abetz has rejected Mr Gray's assertions.

In a book, launched today to coincide with his 80th birthday, Mr Gray criticises Senator Abetz for moving to get rid of him as leader.

He refers to a letter sent by senior party supporters in December 1991 just days before he lost the leadership to Ray Groom.

The letter to Sentor Abetz, who was then party president, expressed concern that his involvement in the leadership breached the party's constitution and platform.

It asked him to defer a parliamentary meeting "which you have forced him to call by the destabilisation which you and the president's standing committee have initiated or encouraged".

"The importance of the letter is that it became a turning point for the Liberal Party in Tasmania, and the ramifications continue to this day," Mr Gray said in this book.

"In essence Abetz ignored the request, and in so doing upset many of the broad grass roots of the party to desist.

"Treated in this manner, hardworking volunteer supporters represented by those signatories, gradually stepped away from their previous levels of contribution and involvement.

"Branches throughout regional areas progressively closed.

"The party is now a much narrower, top-down organisation and much less representative and active in the community because of that."

Senator Abetz was dismissive of the claims.

"Robin's interpretation of the events of the time is interesting, but does not reflect the reality of the issues," he said.

"It is a great privilege to have been the beneficiary of the members' support, as both state president and a senator, and I think they have made their own judgement about those particular events."

Senator Abetz's supporters say Mr Gray "was on the nose with $10,000 cash unexplained in his house" after the Royal Commission into the attempt to bribe Labor MP Jim Cox.

They say Senator Abetz saved the party from bankruptcy and his campaign efforts led to a Liberal landslide victory just months after Mr Gray was replaced by Ray Groom as leader.

In the book, Mr Gray said he was disappointed to be replaced as leader because he had unfinished business.

"I knew full well that I would not emerge as leader, but was determined to see 'the whites of the eyes' of those who were to let me down so badly when I most needed their support," he wrote.

He derides Mr Groom and former Liberal Premier Tony Rundle for "lacking a clear sense of direction that could capture public imagination."

Mr Gray denies he was the instigator of a plot in 1992 by former Liberal MP Bill Bonde which saw Labor and the Greens support Graeme Page as speaker instead of the Liberal's choice the late Michael Hodgman.

"Although repeated again in 2018 (with Sue Hickey), Tasmanians had not seen anything like it in their time," he wrote.

"It remains one of the sadder memories of my time in Parliament."