Michael Spencer, the chief executive of interdealer broker Icap, this morning warned of the crippling effects of a financial transaction tax in Europe, which he added now faces the inevitability of a Greek exit.

On a conference call to discuss Icap's results for the year ended March 31, Spencer said that even with the election of socialist Francois Hollande to the French presidency, there was "no chance a financial transactions tax will hit the UK. David Cameron has said so himself in parliament".