Campaigning in the 2016 United Kingdom European Union membership referendum

Vote Leave was created in October 2015, and was a cross-party campaign, including members of Parliament from the Conservatives, Labour and UKIP.

Founded in July 2015 as The Know, the campaign was relaunched in September 2015 with its present name to reflect altered wording in the referendum question.

Despite its name, it was started by politicians from a mixture of political parties, including Peter Bone, Tom Pursglove and Liam Fox from the Conservatives, Kate Hoey from Labour, Nigel Farage from UKIP, Sammy Wilson from the DUP and George Galloway from Respect.

The Left Leave campaign was chaired by Robert Griffiths, the General Secretary of the Communist Party of Britain.

[31] On 13 June 2016 Mandy Boylett launched a follow-up Brexit song, penning new words to Pink's Get the Party Started.

[32] The new song was immediately reported across the British Press including the Daily Express,[33] City AM[34] A number of politicians, public figures, newspapers and magazines, businesses and other organisations endorsed an official position during the Referendum campaign.

[35][36] On 4 March 2017, the Information Commissioner's Office also reported that it was 'conducting a wide assessment of the data-protection risks arising from the use of data analytics, including for political purposes' in relation to the Brexit campaign.

[37][38] On 21 April 2017, the Electoral Commission announced that it was investigating 'whether one or more donations – including of services – accepted by Leave.EU was impermissible; and whether Leave.EU's spending return was complete', because 'there were reasonable grounds to suspect that potential offences under the law may have occurred'.