Reasons that were cited as justification include campaign finance violations by Vote Leave and Leave.EU, the alleged use of data illicitly harvested by Cambridge Analytica,[4][5] revelations of Russian interference through fake social media accounts and allegedly through funding,[6] arguments that the "Leave" camp promoted misinformation,[7] a gradual shift in public opinion, fuelled in part by demographic changes such as adolescents who were too young to take part in the first referendum reaching voting age,[8] and that the eventually-arranged terms of Brexit were unknown at the time of the original vote.
[9][10] The most widely discussed proposal was a referendum between "Remain" and "Accept the deal", which was promoted by the People's Vote pressure group.
A few weeks after the referendum, an e-petition originally set up beforehand on 25 May 2016 by a member of the Leave-supporting English Democrats[failed verification] demanding it be re-run in the event that a supermajority was not reached became the most popular petition on the site, receiving 4,150,262 signatures.
[2] The leader of the Trades Union Congress, which is closely allied with Labour, said at its 2018 conference that it would declare in favour of a second referendum if the government failed to get "the deal that working people need".
[23] The following week, the Labour Party announced that it would put forward its own second referendum amendment if its attempts to safeguard workers' rights, Single market access and Customs Union membership failed.
[11] The proposal for a referendum on the withdrawal agreement was first put to Parliament on 14 March 2019 in an amendment (tabled by Sarah Wollaston) to the motion to request the first extension to the Article 50 deadline, where it was rejected by 85–334, with the Labour Party (and all but 43 of its MPs) abstaining.
[25][26] On 27 March and 1 April 2019, a series of indicative votes was held, both times including a referendum on the withdrawal agreement among the proposals.