Since 1977, both pro- and anti-European views have had majority support at different times, with some dramatic swings between the two camps. In the United Kingdom European Communities membership referendum of 1975, two-thirds of British voters favoured continued EC membership. The highest-ever rejection of membership was in 1980, the first full year of Prime Minister Margaret Thatcher's term of office, with 65% opposed to and 26% in favour of membership. As a member of European Union, the United Kingdom never adopted the use of the euro or joined the Schengen Area. The Schengen agreements allowed citizens of countries in the European Union to travel without border controls.