A senior official from the Financial Conduct Authority has branded proposed EU caps on dark pool trading as a ‘clunky’ policy measure, in a sign of the growing tensions between the UK and European regulators on new trading rules.

David Lawton, director of the FCA's markets division and a member of the European Securities and Market Authority's board of supervisors, made the comments concerning new rules contained in a revised version of the Markets in Financial Instruments Directive at a House of Lord's committee meeting Tuesday.