In an interview with Sky News, the musician said he "wants to pay for scans" and has asked people to come forward, but admitted that he "hasn't gotten very far".

Sir Rod, 78, paid for members of the public to have scans in a mobile unit at the Princess Alexandra Hospital in Essex in February.

He pledged to help during a Sky News phone-in about the state of the NHS in January, having just returned from a scan himself.

On Thursday, he said: "We haven't got very far unfortunately, I thought there would have been a lot of people calling me up. We just did one at Harlow and I've got another one somewhere near Glasgow coming up. I want to pay for a scan so just get in touch."

Asked whether he supports the 72-hour junior doctors' strike in England, which is currently under way, Sir Rod said: "Of course I do, I'm a working-class guy… this is a chance to get them even. Where's all the money gone? I know I pay millions in taxes, so where's it all gone?"

The walkout, which lasts until 7am on Saturday, comes amid the threat of further strikes throughout the summer if the government doesn't budge on its pay offer.

Sir Rod is 'a bit of a fan' of Boris Johnson

Sir Rod also said he is still "a bit of a fan" of Boris Johnson but added that he's "not surprised he's in big trouble now", after a parliamentary inquiry said the former prime minister deliberately misled MPs with his partygate denials during the COVID pandemic.

He said: "I was and still am a bit of a fan of Boris because I think he has wonderful charisma but you knew what you were getting yourself into with Boris so it's not unusual. He's told a few porkies over the years and so I'm not surprised he's in big trouble now - how's he going to make a comeback? I don't know."

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The privileges committee of MPs found Mr Johnson's breaches serious enough to recommend a suspension of 90 days if he were still an MP - far exceeding the period needed to trigger a recall petition and possible by-election.

Sir Rod also spoke about his upcoming UK summer tour which he described as his last rock 'n' roll tour. When asked whether it was an "end of an era", he replied: "you could put it that way".

The musician said: "It's just I've been singing Hot Kegs and Maggie May for 50-odd years, it's time for a change, all things must end and I want to sing jazz… so we're going to do that."

When asked about where he stands on experimenting with AI in music, Sir Rod said "as far as music goes I don't really care", adding: "no one sounds like me".

He told Sky News: "It's scary, it could be the destruction of mankind as we know it, apparently, so we have to protect ourselves. As far as music goes I don't really care, no one sounds like me."