Robert F Kennedy Jr could assume some control over US health and food safety in a second Trump administration, according to reports on Saturday, alarming Democrats who believe the former environmental lawyer and independent presidential candidate could be empowered to act on his vaccine-sceptical views.

According to the Washington Post, Kennedy has met with Trump transition officials to help draw up an agenda for a new administration and could take a broad “health tsar” position that would not require confirmation by the Senate.

Kennedy, who ended his White House bid and endorsed Trump, and his advisers have also been drafting 30-, 60- and 90-day plans for a second Trump term, the outlet reported, citing a source “familiar” with the planning process.

Kamala Harris slammed the idea, saying Friday that Kennedy is “the exact last person in America who should be setting healthcare policy for America’s families and children”.

The Democratic candidate further described Kennedy as “someone who has routinely promoted junk science and crazy conspiracy theories”.

Last week, Kennedy warned in a post on X that the “FDA’s war on public health is about to end. This includes its aggressive suppression of psychedelics, peptides, stem cells, raw milk, hyperbaric therapies, chelating compounds, ivermectin, hydroxychloroquine, vitamins, clean foods, sunshine, exercise, nutraceuticals and anything else that advances human health and can’t be patented by Pharma.”

He added: “If you work for the FDA and are part of this corrupt system, I have two messages for you: 1 Preserve your records, and 2 Pack your bags.”

Ted Kennedy Jr, a cousin of RFK Jr and a healthcare lawyer, said he was “deeply concerned” about Trump’s choice.

“We can’t put anyone in charge of healthcare who doesn’t understand how doctors and scientists develop best practices and keep us safe, and has no medical background and no knowledge about how health care is organized, delivered and paid for,” he told Stat.

But Trump seems determined. He told rightwing figure Tucker Carlson last week that Kennedy was “going to work on health and women’s health”.

“He really wants to with the pesticides and the, you know, all the different things. I said, he can do it,” Trump said. “He can do anything he wants. He wants to look at the vaccines. He wants – everything. I think it’s great. I think it’s great.”

“He’s a great guy. I’ve known him a long time. And all he wants to do – it’s very simple – he wants to make people healthy,” Trump told NBC News on Friday. Campaign officials previously told the outlet that Kennedy might spearhead an “Operation Warp Speed for childhood chronic disease”, a reference to the Trump administration’s $20bn Covid vaccine development program.

But the discussion over a potential role for Kennedy in a new Trump administration has also raised the topic of the response to the 2020-21 Covid-19 pandemic that has been largely absent from the campaign trail.

JD Vance, Trump’s vice-presidential pick, expressed scepticism about the Covid vaccine during a sit-down with podcaster Joe Rogan released on Thursday.

“I took the vax, and you know, I haven’t been boosted or anything, but the moment where I really started to get red-pilled on the whole vax thing was the sickest that I have been in the last 15 years by far was when I took the vaccine,” the Ohio senator told Rogan.

Kennedy, who has also expressed doubts about Covid vaccines, told a rally last week that Trump had promised him “control” of public health agencies like the Department of Health and Human Services and the Department of Agriculture.

Howard Lutnick, the Trump transition team co-chair, confirmed to CNN this week that he’d spent two-and-a-half hours with Kennedy “and it was the most extraordinary thing”.

“I said: ‘So, tell me. How’s it going to go?’ And he said: ‘Why don’t you just listen to me explain things,’” Lutnick said. He did not deny that Kennedy was correct to say he would lead public health agencies in a Trump administration.

“I think it’ll be pretty cool to give him the data. Let’s see what he comes up with,” Lutnick added.

In a statement, Trump campaign spokesperson Karoline Leavitt said there were “no formal decisions” about potential Trump administration appointments. But she added that the former president “has said he will work alongside passionate voices like RFK Jr to make America healthy again by providing families with safe food and ending the chronic disease epidemic plaguing our children”, referring to type 2 diabetes.