A campaigner, who admits to being “a right pain in the arse”, has been sacked from a committee in the Australian state of Victoria after threatening to produce car bumper stickers mocking alleged inaction over LGBT bullying.

Rob Mitchell claims he was dismissed from the Gay, Lesbian, Bisexual, Transgender and Intersex Health and Wellbeing Ministerial Advisory Committee for “asking inconvenient questions” and criticising Victoria’s coalition government in a radio interview last month.

The Age reports during the interview, Mr Mitchell said he had struggled to get the committee to advance the Safe Schools coalition programme, which teaches students about same-sex relationships and guards against LGBT bullying.

He said working for the advisory group had been “mind numbing”.

Mr Mitchell also slammed State Premier Denis Napthine and Victoria’s Health Minister David Davis for their approach on tackling HIV transmission in Victoria, claiming their appearance at a Pride festival amounted to “window dressing of the worst sort” in order to gain votes.

The campaigner said that when the deputy chair of the committee, Associate Professor Ruth McNair, cancelled a meeting he had set up with the Department of Education in February to discuss the school programme, he then called the university where Professor McNair works to ask for her photograph so he could make a bumper sticker with it.

“He wanted my photo, said I was a load of crap, [he] wanted to put it on a bumper sticker and that I was undermining the health and wellbeing of young people,”  Professor McNair said on Tuesday.

“It was completely inappropriate. I didn’t respond of course because it’s not worth responding to that sort of behaviour. It’s just an example of the sort of lengths he will go to to make a point,” said the GP who works at Melbourne University.

Mr Mitchell said although he could be a “right pain in the arse” at times, he was frustrated that the committee had not followed its work plan.

He said the Safe Schools programme had only reached about 120 of Victoria’s 2,200 schools to date and that it required about 5 million AUD (£2.68m) a year to expand.

The campaigner said he did not call Professor McNair “crap”, but said her work had been “crap”.

Mr Mitchell denies accusations of aggression but said he could be rather “combative and straight to the point”.

“The only reason I’m frustrated is because I know this problem is fixable. It comes down to a lack of backbone,” he said.

A spokesman for Health Minister David Davis said: “The minister has carefully considered advice of the Department of Health, committee chair Mike Kennedy, deputy chair Ruth McNair, and the committee’s working group chairs, regarding Mr Mitchell’s membership and behaviour towards his colleagues on the committee and has determined that the termination of his membership is the best course of action so the committee can continue its important work on developing rigorous and expert advice to government regarding the health and wellbeing of GLBTI Victorians in a harmonious way.”