Question: when did the labour party come to power

title: Labour Party (UK)
text: The day after 7 May 2015 election , Miliband resigned as party leader . Harriet Harman again became acting leader . The Labour Party held a leadership election , in which Jeremy Corbyn , then a member of the Socialist Campaign Group , was considered a fringe hopeful when the contest began , receiving nominations from just 36 MPs , one more than the minimum required to stand , and the support of just 16 MPs . However , he benefited from a large influx of new members as well as new affiliated and registered supporters introduced under Miliband . On 12 September , he was elected leader by a landslide . Membership numbers continued to climb after the start of Corbyn 's leadership .