From: news.bbc.co.uk

But the US Treasury said it would "not support" a transaction tax and Canada's finance minister said it was "not an idea we would look at".

Chancellor Alistair Darling said the International Monetary Fund would now consider the possibility of introducing an international transactions tax.

"We do need to look ahead to see whether or not it would be possible to develop a transaction tax that would have to be universal, it would be comprehensive in its scope and would have to be compatible of financial stability as well as making sure that it is fair and didn't distort things," he said.

"This is clearly work in progress, it will take time to develop but it is, I believe, an important piece of work so that we can see how better to ensure the financial services industry both contributes to the well-being of the world as a whole as well as making sure that, if we have difficulties in the future, they make a contribution to that as well."