The G20 Summit is underway in Cannes, France with attendees including British Prime Minister David Cameron, French President Nicolas Sarkozy and German chancellor Angela Merkel, and the talks are set to be dominated by the current financial crisis in the Eurozone.
The Love Actually star has also travelled to France as part of a campaign in favour of a new Robin Hood Tax on the rich, which would see a levy imposed on large financial transactions and distributed among good causes, and he is adamant world leaders need to agree to the proposals.
He tells BBC Breakfast, ""This is a 50 pence tax on every thousand pounds generated in cyberspace... It would be at each country's discretion to distribute the money as they see fit... a kind of institutionalised charity. This tax would fall quite squarely on the broad shoulders of the rich... it's also supported by some serious people like Warren Buffett... Bill Gates is about to address leaders at the summit about his support for the tax... It would be a wonderful, beautiful inexpressibly fabulous thing.""
Nighy also praised campaigners around the world who have been demonstrating against corporate greed, with the Occupy Wall Street protest in New York and the camp outside St Paul's Cathedral in London.
He adds, ""The dignity and restraint of the protests have had an enormous effect on people around the world, not only on the Robin Hood Tax (campaign).""