The health secretary has accused Reform UK leader Nigel Farage of having a “miserablist, declinist” vision of the UK, in the most direct attack yet by a senior Labour figure.

Wes Streeting made the comments in a speech on Saturday at the Fabian Society, a left-leaning organisation, warning of the need to take the “populist right” seriously.

He accused Farage of not believing in a universal health service “free at the point of use”, and of having a “poverty of ambition” for the UK that Labour “utterly rejects”.

Farage responded by saying it was Labour who had the miserable vision and that Reform was the “optimistic alternative”.

“The crux of Farage’s argument is this: what was possible in the 20th Century isn’t possible in the 21st,” Streeting told his audience.

“People shouldn’t have to choose between a health service that treats them on time and an NHS free at the point of use.”

Nigel Farage has previously suggested that the NHS could be replaced by an insurance-based system. However, Reform policy documents say healthcare should always remain free at the point of delivery.

“The populist right are coming for us and we need to be serious about beating them,” Streeting said, adding that Farage could be defeated by “turning around the NHS”.

The health secretary spoke of meeting people every day on the campaign trail “who had been let down by the NHS”, being made to wait for ambulances or operations.

Some voters had “the most appalling experiences, and because of how they’ve been treated, they were voting for Reform”, he said.

Farage wrote on social media following the speech that Streeting “is so scared of Reform that he has now resorted to lying about our plans for the NHS”.

“Let me be clear, the NHS will always be free at the point of delivery under a Reform government,” he added.

Farage has said that his ultimate goal is to win the next general election, building on the momentum that Reform has recently enjoyed.

While his party has largely been viewed as a threat to the Conservatives, in recent weeks it has been gaining ground on both Labour and the Tories in opinion polls.

One recent YouGov poll, which asked people who would make the best prime minister, suggested similar levels of support for both Nigel Farage and Sir Keir Starmer.

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Shortly after Streeting began his speech in the historic Guildhall in central London, a climate protester climbed onto her chair and began heckling him.

“When we voted for Labour, we voted for change,” the demonstrator shouted. “But your government continues to subsidise the Drax power station.”

The North Yorkshire wood-burning power station receives large government subsidies – but has been accused of using wood from unsustainable sources and was fined last year after Ofgem found it had given the watchdog inaccurate data on the type of material it used.

Streeting did not halt his speech, and the woman was ushered from the hall as she continued to warn about “climate breakdown”.

Almost immediately, a second woman stood up and began shouting. She too was led out.

The interruptions prompted the health secretary to deviate from his prepared remarks, saying he was “in politics to make real change, not shout from the sidelines”. The audience then applauded.

He later joked that he was surprised there were not more protesters.