Would visas be required when travelling between the UK and EU countries, if the UK votes to leave? How would this apply between the Republic of Ireland and Northern Ireland? Evan Davis discusses with Armed Forces Minister Penny Mordaunt, Richard Walton, who was Counter Terrorism Commander for the Metropolitan Police until January, former director of Liberty Shami Chakrabarti and Rob Wainwright who is director of Europol, the law enforcement agency of the European Union. Newsnight is the BBC's flagship news and current affairs TV programme - with analysis, debate, exclusives, and robust interviews. Subscribe to our YouTube channel for highlights and bonus videos bbc.in/1iouM30 Follow us on Twitter @BBCNewsnight for the latest updates on #newsnight Add us on Snapchat - our username is 'BBCNewsnight' And follow on Facebook for our best material, an early heads up on what's coming up, and to join in our debates www.facebook.com/bbcnewsnight