UK’s European Commissioner Lord Hill is to stand down saying ‘what is done cannot be undone’ after the UK votes to leave the European Union.In a statement, he said he did not believe it was right for him to carry on with his work as the commissioner in charge of financial services.But he will stay on for a period of weeks to ensure an orderly handover.A close ally of Prime Minister David Cameron, Lord Hill had argued for the UK to remain in the EU.