Election pledges mean nothing when Brussels cracks the whip.
If pre-existing British law conflicts with a new Euro law, our law HAS to be changed to conform to the edict from Brussels. Most Euro laws are enacted by the Commission, a group of bureaucrats. British Commissioners swear an oath NOT to act in Britain's interests. Other laws are enacted by the Council of Ministers where Britain has one voice out of fifteen. Despite promises about 'subsidiarity', no Euro diktat has been repealed since Maastricht.