Robert F. Kennedy Jr. is expected to win Senate approval to be US health secretary
Robert F. Kennedy Jr. is expected to win Senate approval to be US health secretary AFP

The Republican-controlled US Senate was expected Thursday to approve vaccine conspiracy theorist Robert F. Kennedy Jr. as health secretary, despite major concerns from both political parties and many in the medical and scientific communities.

Kennedy squeaked through a crucial preliminary vote last week by the Senate Finance Committee, setting up the vote by the full upper chamber, which is controlled by US President Trump's Republicans.

The 71-year-old nephew of the assassinated president John F. Kennedy is expected to win approval as Republicans yet again back Trump and his latest cabinet pick.

The vote is expected around 10:30 am (1530 GMT).

An environmental lawyer by trade with no medical background, Kennedy has spent years professing conspiracy theories linking vaccines and autism, and most recently spread misinformation about Covid-19 vaccines.

His nomination has faced vocal opposition from both parties, with Republicans particularly eying his past support for abortion, his record suing big business and his 2023 run for president as a Democrat.

Nine months ago, Trump was calling Kennedy "one of the most Liberal Lunatics ever to run for office."

Beyond vaccines, Democrats point mainly to sexual misconduct allegations, Kennedy's suggestion that Covid-19 was designed to spare Jews, his linking of school shootings to anti-depressants and bizarre incidents involving dead animals.

Last year 77 Nobel prize winners sent an open letter to the Senate opposing his nomination and warning he could place the public's health "in jeopardy."

"He's a frightening man, (a) dangerous man, and I think he'll do harm," said Paul Offit, head of the Vaccine Education Center at Children's Hospital of Philadelphia.

Critics accuse Republicans of being negligent.

"They are looking the other way. They are choosing to pretend like it is in any way believable that RFK Jr. won't use his new power to do exactly the thing he has been trying to do for decades -- undermine vaccines," said Democratic Senator Patty Murray.

The Republican-controlled Senate has so far approved all of Trump's cabinet nominations over howls of protest from Democrats who have attacked the candidates' lack of experience and, in some cases, questioned their patriotism.

On Wednesday it gave the green light to Tulsi Gabbard as Trump's choice to lead the intelligence services, despite criticism over her inexperience and past support for US adversaries Russia and Syria.

Gabbard's success was seen as another powerful demonstration of Trump's iron grip on his party, after he pushed through a slate of some of the most contentious cabinet nominees in modern history.

The president proposed a defense secretary accused of sexual assault, an attorney general suspected of trafficking a minor for sex, and an FBI chief alleged to be motivated by political revenge. All were also widely criticized for their lack of experience.

Only the suspected sex trafficker -- former Florida congressman Matt Gaetz -- has so far been rejected by the Senate.