European brokers remain in the dark as to how a new French financial transaction tax will be implemented just two and a half weeks before it is due to come into effect. Two brokers have privately described the ongoing confusion as “mayhem”.

Brian Gallagher, managing director of European electronic trading at Morgan Stanley, said: "We understand the intention of the tax, but the execution has not been as well constructed and there has been a lack of clarity in terms of who is affected, how they are affected and which securities are included."