The National Health Service may have to be replaced with an insurance system within the next decade, Nigel Farage has said.

The Ukip leader said anyone who believed the current way of paying for medical care in the UK had to be preserved “frankly isn’t thinking” and that he was open to “rethink[ing] the whole thing”.

Mr Farage also likened Ukip’s rise to that of Margaret Thatcher.

“There are times in a country’s politics where radical change is needed,” he told BBC’s Newsnight programme on Thursday evening.

“I lean towards Government doing less. I believe if you lift off the backs of the British people excessive regulation and the wrong levels of tax they will do better.”

He said increased spending on the NHS had brought few rewards and that a larger population might make the NHS unworkable.

“In 10, 20, or 30 years time, if the population of this country is going to be 80m, 90m, or 100m, we may have to rethink the whole thing,” he said.

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“Right now what we have is a National Health Service where between 2000 and 2012 we doubled expenditure and we finished up with fewer beds. The priority now is to run it better.

“I could conceive in the future of anything happening in any policy area, and anybody in politics who tells you that what is here today must be in stone forever frankly isn’t thinking.”

Last month Mr Farage told BBC Radio 4 that there was “no question” about whether the UK needed to explore different ways to deliver healthcare.

In 2010 Ukip’s manifesto, since disowned by the party, called for the introduction of Health Credit Vouchers, which would allow people to opt-out of paying for the NHS if they did not use it.

The party is set to announce its full health policy for 2015 in its manifesto in the coming months.

In a recent international study by the US-based Commonwealth Fund the NHS ranked as the most efficient healthcare system out of 11 developed countries' systems examined.