British finance minister George Osborne wants to make currency exchange rate manipulation a criminal offence in the UK.
But he has rejected plans by Brussels to bring in four-year jail terms for fixing financial markets.
Osborne does not want those EU laws to apply in London, the biggest currency trading centre.
He has already clashed with the European Union over laws limiting bankers’ bonuses. Britain has the right to opt out of rules involving criminal penalties.
Osborne set out the proposals in a speech at the Lord Mayor of London’s ornate Mansion House residence, stressing the importance of integrity in Britain’s financial markets to the economy as a whole.
More than 40 currency dealers around the world have now been fired or suspended following claims that traders used client order information improperly to attempt to manipulate prices. But no-one has been prosecuted under England’s existing laws.
Rejecting EU proposals is likely to please MPs in Osborne’s Conservative Party who oppose giving more powers to Brussels.