[1] However, a subsequent bill with the same objective, the European Union Referendum Act 2015, was later introduced to the House of Commons by the newly elected Conservative government in May 2015 was passed and received royal assent on 17 December 2015.

[2] In May 2013, the Conservative Party published a draft EU referendum bill and outlined their plans for renegotiation and then an in-out vote if returned to office in 2015.

[7] Originally the bill gave the question to appear on ballot papers: Do you think that the United Kingdom should be a member of the European Union?

In the autumn of 2013 the Electoral Commission published a report which studied and tested the wording of the proposed question contained within the bill and presented two possible revised options.

with the responses (to be marked with a single (X)): Aros yn aelod o'r Undeb Ewropeaidd Gadael yr Undeb Ewropeaidd The Electoral Commission tested this option but were unable to fully able to explore its full viability in the time available however it would be this exact wording and responses that would later be used and appeared on ballot papers for the 2016 EU Referendum under the European Union Referendum Act 2015.

Labour peer Baroness Quinn also criticised the bill by describing the proposed commitment as "alarming" and was "highly irregular in singling out a date".

[22] In May 2015 the Conservative Party led by then Prime Minister David Cameron won a small but unexpected overall majority in the 2015 general election which contained a manifesto promise to hold a renegotiation of the UK's membership of the EU to be followed by a in-out referendum.

It was fulfilled when a Referendum Bill was contained in the Queens speech three weeks after the election with both Labour and the Liberal Democrats dropping their previous opposition.