Europe's highest court rejected on Wednesday Britain's legal challenge to the introduction of a financial transactions tax (FTT) in Europe, dealing a blow to London's efforts to stop a levy that may hit its trading business.
In the ruling, the European Court of Justice said that Britain could not at this stage block an attempt by 11 countries to impose the levy on the grounds that it would also hit trades involving banks or brokers in London.
The countries that signed up to the project, it said, had yet to finalize how the tax will work.
"The Court dismisses the United Kingdom's action," the court said in a statement.
"The Court finds that the contested decision does no more than authorize the establishment of enhanced cooperation, but does not contain any substantive element on the FTT itself."