This week, Brown's struggling government published a major review of the NHS -- set up after World War II to provide free treatment for all -- by health minister and top surgeon Lord Ara Darzi.

The giant provider, the world's fourth-largest employer with a budget of nearly 100 billion pounds a year (125 billion euros, 199 billion dollars) in England alone, is battling an ageing population, rising treatment costs and more informed patients questioning their care.

But the NHS, which provides mostly free medical care to all Britons and is funded from general taxation, is still highly regarded.

Former prime minister Margaret Thatcher's finance minister Nigel Lawson once said it is "the closest thing the English have to a religion".

A Daily Telegraph/You Gov poll this week found 58 percent of Britons had used it in the last three months and 81 percent were satisfied with their treatment.

Brown has led praise for the system, invoking personal experience -- his sight was saved by NHS surgeons after a rugby accident when he was 16 -- and saying he was "proud" it was set up by a Labour government.