Deputy Leader of the Labour Party (UK) of the Party until a new leader is elected. If a vacancy in the leadership occurs while the Labour Party is in government, then the Cabinet, in consultation with the National Executive Committee of the Labour Party, chooses a new leader, who serves until a new leader is elected. To date, the only Deputy Leaders who have gone on to become the elected leader of the Labour Party are Clement Attlee and Michael Foot. Margaret Beckett briefly served as Labour leader following the unexpected death of John Smith in 1994. Harriet Harman was leader after Gordon Brown resigned in 2010
Labour Party leadership of Jeremy Corbyn after Corbyn's leadership election, there was a large increase in the number of Labour Party members; from 201,293 on 6 May 2015 (the day before the 2015 general election) to 388,407 on 10 January 2016. Local Labour constituency offices have attributed this rise mainly to the "Corbyn effect". Reflecting an increased interest among the young, university cities and towns recorded some of the biggest rises. Following Corbyn's election as Leader of the Labour Party, Bath's Labour Party membership increased from 300 to 1,322 and Colchester's from 200–250 to 1,000. Momentum, a grassroots movement supportive of Corbyn and the Labour Party,