British Prime Minister Keir Starmer warned on Thursday that the UK's state-run National Health Service must "reform or die", after an independent report said the venerated institution was in a "critical condition".

Starmer, whose Labour party was elected by a landslide in July, promised "the biggest reimagining" of the NHS since it was founded 76 years ago.

His speech in central London followed the publication of a 142-page investigation which found that the health of Britons had deteriorated over the past 15 years.

The report's author, Ara Darzi, an unaffiliated Lord in parliament's upper chamber, said the NHS had fallen into "disrepair" due to a lack of investment compared to peer countries, top-down reorganisation and the pandemic.

"What we need is the courage to deliver long-term reform -- major surgery not sticking plaster solutions," Starmer said, adding the service would take a decade to rebuild.

"The NHS is at a fork in the road, and we have a choice about how it should meet those demands. Raise taxes on working people to meet the ever-higher costs of ageing population -- or reform to secure its future. Working people can't afford to pay more, so it's reform or die."

Starmer outlined the three areas of reform for a 10-year plan to "turn around the NHS", whose universal model is a source of pride, despite its shortcomings in meeting demand.

He said the NHS would fully switch from analogue to digital, move more care from hospitals to communities and be "bolder" in switching the focus from sickness to prevention.

Starmer insisted the reforms would not mean "abandoning the founding ideal" of the NHS, which is free treatment at the point of need and added he would not spend more money "without reform".

"The 2010s were a lost decade for our NHS, a lost decade in which the Conservatives left the NHS unable to be there for patients today and totally unprepared for the challenges and opportunities of tomorrow," he added.

Darzi's report notes the NHS was seeing a surge in patients suffering multiple long-term illnesses such as diabetes and high blood pressure.

It said the UK has higher cancer rates than other countries and was lagging behind in its treatment of major conditions.

It also noted that waiting lists have swelled to 7.6 million and that a 10th of patients at accident and emergency wards now wait 12 hours or more before being seen.

Darzi said that he was "shocked" by what he discovered but added the NHS's vital signs "remain strong". (AFP)