described by UKIP leader Nigel Farage as "disastrous" for Cameron, and the leaders of the other main parties. In September 2014, the Unionist side, championed by Labour as well as by the Conservative Party and the Liberal Democrats, won in the Scottish Independence referendum by 55% No to 45% Yes on the question "Should Scotland be an independent country". This can be seen as a victory for British Unionism, a core part of traditional Conservative ideology, and also for Cameron as the incumbent Prime Minister. At the 2015 general election, the Conservatives won a majority of seats in the House of Commons and formed a majority government under Cameron. The party increased its national vote share, becoming the first incumbent party to do so since 1900. The result was unexpected and exceeded even the party leadership's expectations, as most polls had predicted a hung parliament. This was also the first general election since 1992 in which the Conservatives had won an overall majority, although the vote share of 36.9% was lower than the previous four Conservative majority governments under Thatcher and Major. In March 2017, the party was fined £70,000, the largest fine of this sort in British political history, after an Electoral Commission investigation found "significant failures" by the party to report its 2015 general election campaign spending. On the morning of Friday 24 June 2016, Cameron announced his intention to resign as Prime Minister, after he failed to convince the British public to stay in the European Union, and subsequently the Conservative Party leadership election was announced with Theresa May, Michael Gove, Stephen Crabb, Liam Fox and Andrea Leadsom confirmed as the official contenders to be his successor with Boris Johnson ruling himself out of the process. After Crabb withdrew, Fox and then Gove were eliminated in successive ballots by Conservative MPs, leaving Leadsom and May as the final candidates to be put before the wider Conservative Party membership. Leadsom subsequently withdrew from the contest on 11 July. Theresa May (2016–2019) On 11 July 2016, Theresa May became the leader of the Conservative Party with immediate effect following the withdrawal from the leadership election of her sole remaining opponent, Andrea Leadsom. Appointed Prime Minister of the United Kingdom on 13 July 2016, May promised social reform and a more centrist political outlook for the Conservative Party and its government. In a speech after her appointment, May emphasised the