How could a new referendum on Britain's relationship with Europe work? As pressure mounts on Theresa May to seal an agreement on Brexit, there are growing calls for a further referendum on the issue. From across the political spectrum, MPs, trade unions and campaigners are demanding another vote on the terms of the deal, or lack of one. In the Briefing Room, David Aaronovitch examines the mechanics of this hypothetical proposition. What would the procedure be to trigger another referendum and how would it be organised? And is there enough time?