In contrast, the legislation which provided for the referendum held on AV in May 2011 would have implemented the new system of voting without further legislation, provided that the boundary changes also provided for in the Parliamentary Voting System and Constituencies Act 2011 were also implemented. In the event, there was a substantial majority against any change. The 1975 referendum was held after the re-negotiated terms of the UK's EC membership had been agreed by all EC Member States and the terms set out in a command paper which later became known as the Referendum Act 1975 and was passed by both Houses.