National banking watchdogs still have too much discretion in implementing European law and “more needs to be done” to complete a harmonised financial services rulebook across the eurozone, according to the head of the monetary union's Single Supervisory Mechanism.

Danièle Nouy, chair of the European Central Bank's supervisory board, on Thursday asked the European Parliament to give it more power to overcome the differences in the way pan-eurozone rules are implemented by member states.