Gang of Eight

In UK politics, the Gang of Eight was a breakaway group of eight Blairite or "soft left", Labour MPs many of whom were prominent Labour politicians, who resigned the Labour whip to join the Libdems in October 2018 in protest to the perceived radicalism of Jeremy Corbyn's leadership, as well as the alleged mishandling of antisemitism complaints in the party.

The term Gang of Eight is a reference to the Gang of Four, four moderate Labour politicians who left the party in 1981 to form the Social Democratic Party as a response to the similarly criticised leadership of then-Labour leader Michael Foot.

Background
Following Labour's worse-than-expected results in the 2015 general election, which saw the party make a net loss of 61 on their 2010 results, Ed Miliband resigned as Labour leader, triggering a leadership election. In the election, Islington North MP Jeremy Corbyn, who was considered to be on the left-wing fringe of the party, was elected leader of the Labour Party in a shock victory.

Throughout Corbyn's time as leader, the Labour Party was repeatedly under fire for allegations of antisemitism, and consistently polled well behind the Conservatives. Despite minor gains in the 2018 local elections, after Boris Johnson's election as Conservative leader, Labour remained up to 20 points behind the Conservatives in opinion polling. This raised growing questions around Corbyn's electability, with the antisemitism allegations, the party's staunchly left-wing platform, and Corbyn's unpopularity raised as potential issues. In June 2018, Labour lost the previously safe seat of Lewisham East to the Liberal Democrats in a by-election.

Aftermath
Immediately following the MPs defection, there was a surge in support for the Liberal Democrats in the polls, with one poll placing the party 2% ahead of the Conservatives on 35%, with Labour on just 18%. One of the Eight, Liz Kendall would go onto stand for leader of the Liberal Democrats in the Jan 2019 leadership election against Ed Davey, winning narrowly. In the 2019 general election, six of the eight defectors would stand as Liberal Democrats, all of which, including Kendall, would lose their seats. Overall, the party would end up losing an addition 3 seats, as well as 1.8% of the popular vote. According to The Telegraph, one of the reasons for the Liberal Democrat losses, particularly in the South West, was the association of Kendall as a former Labour MP, although this analysis was disputed by The Guardian.