Amid the chaos that is the UK’s Brexit debate, calls for a second referendum are amplifying. Amber Rudd has become the latest to break from her cabinet colleagues by saying that there’s a “plausible argument” for a second referendum if Theresa May’s Brexit agreement with the EU gets rejected by MPs. Would that be an unprecedented development? It has actually occurred several times before in several European countries. Ireland is probably the most notable example. It is obliged to put treaties to a vote before they can be implemented as the country needs to change its constitution. Irish voters rejected the Treaty of Nice in 2001 before subsequently approving it in 2002. A similar change of heart happened when the Lisbon Treaty was passed in 2009 after being rejected in 2008. Scandinavia also has experience with second referendums and in Norway, the public said no to EEC/EU membership twice in 1972 and 1994. Denmark also held a second vote on the Maastricht Treaty in 1993 after rejecting it in 1992.