But critics argue the proposed tax would impede the global financial markets that help lubricate an increasingly interdependent world economy.
Our correspondent says the idea has been received politely by the finance ministers - but several made remarks which suggest that other ways of tacking the problem are rather more likely to be adopted.
Canadian Finance Minster Jim Flaherty said the UK plan was "not particularly attractive to me as finance minister in Canada, because we're not a government that has raised taxes".
The British Bankers' Association has also cast doubt on the effectiveness of such levies, which Chief executive Angela Knight "don't work as they require perfect or near-perfect global implementation".
The G20 countries also promised to step up efforts to tackle climate change and "work towards an ambitious outcome" at next month's climate conference in Copenhagen.
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