The voters may have other ideas.
Sept – 2000 A referendum on joining the euro was held in Denmark. It was rejected by 53.2% of voters with a turnout of 87.6%. https://en.wikipedia.org/wiki/Danish_euro_referendum,_2000
June 2005 - Dutch consultative referendum on whether the Netherlands should ratigy the Treaty establishing a Constitution for Europe was rejected by 61.6% of voters , on a turnout of 63.3%.
March 2010 -The Icelandic loan guarantees referendum, was held to approve the terms of a state guarantee on the obligation of the Depositors' and Investors' Guarantee Fund in particular a €3.8 billion loan (€ 11,964 per person) from the governments of the United Kingdom and the Netherlands to cover deposit insurance from depositors from those countries. The proposal was resoundingly defeated, with 98% voting against. https://en.wikipedia.org/wiki/Icelandic_loan_guarantees_referendum,_2010
September 2014 - Scotland voted to stay in the United Kingdom after voters decisively rejected independence.
July 2015 – Greek referendum on the terms of the austerity required in debt renegotiations with its oficial creditors
2017 – UK referendum on the EU as David Cameron has decided to put Britain’s future in the EU to the British voters.
More referenda in the European Union https://en.wikipedia.org/wiki/Referendums_related_to_the_European_Union