Robert F Kennedy Jr will admit all his children are vaccinated in an attempt to convince senators he is not “anti-vax”.

Mr Kennedy, one of Donald Trump’s most controversial cabinet picks, is vying to become America’s next health secretary but has faced fierce criticism for making unfounded claims about vaccine safety, including that they cause autism.

The former environmental lawyer has instead sought to shift focus onto his promise to tackle America’s “chronic disease epidemic” and dependence on ultra-processed foods.

According to Fox News, he is set to tell the senate finance committee on Wednesday that “all of my kids are vaccinated, and I believe vaccines have a critical role in healthcare”.

Mr Kennedy can only afford to lose the support of three senators given the Republican party’s slim majority in the Senate. Republican Senators Mitch McConnell, a polio survivor, and Bill Cassidy, a Louisiana doctor, have been non-committal about their vote.

Hours before his hearing, his cousin Caroline - daughter of former president John F Kennedy - said he was a “predator” who put mice in a blender to feed his hawks. He was also described as “nuts” in a comment piece by the Trump-supporting New York Post.

His first hearing is expected to start at 10am local time (3pm in the UK) ahead of a second appearance on Thursday.