Harriet Harman became the Leader of the Opposition and acting Leader of the Labour Party following the resignation of Gordon Brown on 11 May 2010, pending a leadership election subsequently won by Ed Miliband. Miliband emphasised "responsible capitalism" and greater state intervention to change the balance of the UK economy away from financial services. Tackling vested interests and opening up closed circles in British society were also themes he returned to a number of times. Miliband also argued for greater regulation on banks and the energy companies.

When did Ed Miliband resign?