Forty American billionaires, including Bill Gates, Warren Buffett, George Lucas and Michael Bloomberg, have pledged to give to charity at least half of their fortunes, thought to be worth around £100 billion. Most will go to world health.

Charitable giving totals 2.2% of Gross Domestic Product in the USA, compared with 1.3% in Britain.

Our Queen has been urged to use her 2012 diamond jubilee to persuade every member of the public to give one per cent of their income to charity, a move that would raise more than £4 billion.