The Labor party has stood down a former Play School host turned ALP staffer for social media posts in which he referred to News24 host Peta Credlin as “a strap on wearing fantasy for Liberals”.

Rhys Muldoon was on Tuesday stood down from his position in Tasmanian senator Richard Dowling’s office after news.com.au first reported the comments.

In 2022, Muldoon used X to make a string of sexist attacks on Credlin, the former chief of staff to Tony Abbott, writing: “She’s what Liberals think of Margaret Thatcher. They picture her with a strap on, pounding away at their sorry a**ses”. The account has since been deleted.

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Guardian Australia has seen screenshots of the posts before they were deleted. Muldoon has been contacted for comment.

“The tragedy of Peta Credlin … is her belief that anyone other than fetishised old white men think she contributes anything apart from a compromised boner”, he wrote in another.

In a 2023 post he described Country Liberal senator Price as a “quisling” – a traitor who collaborates with enemies – because she did not support the voice to parliament.

News.com.au reported he used the N-word in a 2014 post making fun of Australian legal protection for free speech.

On Tuesday, Dowling said he had stood down the staffer after he became aware of the comments.

“After being alerted to abhorrent tweets from my staffer, I’ve decided to not continue with his casual contract,” he told Guardian Australia in a statement.

“Everyone in public life has a responsibility to do better when it comes to political discourse. The words used were unacceptable at any time.”

Muldoon was a guest at the wedding of prime minister Anthony Albanese and Jodie Haydon, appeared in the TV sitcom Us and Them and, with Kevin Rudd, co-authored a children’s book called Jasper and Abby and the Great Australia Day Kerfuffle. The prime minister’s office was contacted for comment.

In parliament, Albanese said it was “appropriate” that the staffer was stood down.

“When they became public debate today, I wasn’t aware of those comments until they were raised in the media, and neither was Senator Dowling,” he said.

“The comments are completely unacceptable, and Senator Dowling has taken immediate action – and that’s appropriate.”

Speaking to Guardian Australia, Credlin questioned how Muldoon was cleared by ALP vetters.

“I was surprised that someone with that sort of social media history got through Labor’s vetting net and got a job in the first place,” she said.

“I’m pretty disgusted that he was a star guest at the prime minister’s wedding. But it says more about this individual than it does about me.”