LONDON, Feb 24 (Reuters) - Bank of England Governor Andrew Bailey said post-Brexit moves by the European Union to require banks to justify why they are not moving activities away from Britain were of “dubious legality.” Europe’s top banks are being asked to justify why they should not have to shift clearing of euro-denominated derivatives worth billions of euros from London to the EU, a document seen by Reuters on Tuesday showed. “It would be very controversial in my view because legislating extra-territorially is controversial anyway and obviously of dubious legality, frankly, ...” Bailey told lawmakers in Britain’s parliament on Wednesday. (Reporting by David Milliken and Alistair Smout Writing by William Schomberg Editing by Huw Jones)