A tax on banking could be used to pay for combating climate change under plans pushed by British Prime Minister Gordon Brown and French President Nicolas Sarkozy Friday — as Britain almost doubled the cash it put up for short-term funding to help developing countries go green.

Britain's treasury found over $2.4 billion in so-called fast-track funding from 2010 to 2012 for clean fuel projects and to stop deforestation in developing countries, Brown said after an EU summit in Brussels on Friday.

This was a big increase on Britain's initial offer of $1.2 billion for a voluntary international fund to help encourage progress in climate talks at Copenhagen, but Brown suggested that there would be no extra call on taxpayers because the money was already budgeted for.

It means Britain is offering the largest EU contribution to the fund — followed by France and Germany on $1.84 billion each over the three years.

Brown and Sarkozy held a rare joint press conference designed to show that they had put recent differences over EU appointments behind them and called for the International Monetary Fund to research the use of a banking tax as well as aviation and shipping fuel tax to fund longer term climate measures.

In a joint statement, the two leaders declared: "To ensure predictable and additional finance in the medium term to 2020 and beyond, we should make use of innovative financing mechanisms, such as the use of revenues from a global financial transactions tax and the reduction of aviation and maritime emissions and the auctioning of national emissions permits. We will work together on this."

Click here to read more from the Times of London.