I have long campaigned for such a tax - there is now support of over 115 organisations in the UK, the European Commission, millions of ordinary people, 1,000 international economists, hundreds of parliamentarians, campaigners in over 50 countries, world leaders such as Angela Merkel, the Pope, Desmond Tutu and Nicolas Sarkozy, and global figures such as Bill Gates. But we still don’t have the support of the UK Government. Even doubters like Dutch Prime Minister Mark Rutte have U-turned and now favour the tax.
Part of the answer for Cameron's reluctance maybe related to the fact that 51% of Tory Party funding comes from financial sector donors. Please email Cameron here - he needs to show he has the interests of the many at heart not just his City friends.