 Complete the following phrase:  This Act required a referendum to be held on the question of the UKs continued membership of the European Union before the end of 2017. The Bill did not contain any requirement for the UK Government to implement the results of the referendum, nor set a time limit by which a vote to leave the EU should be implemented. Instead, this was a type of referendum known as a pre-legislative or consultative referendum, which enables the electorate to voice an opinion which then influences the Government in its policy decisions. The referendums held in Scotland 1997, 