The dissolution was originally scheduled for 2020, but took place almost three years early following a call for a snap election by Conservative Prime Minister Theresa May which received the necessary two-thirds majority in a 522 to 13 vote in the House of Commons on 19 April 2017.

Notable newcomers to enter the House of Commons in this General Election included future Prime Ministers Rishi Sunak and Keir Starmer, as well as the future parliamentary leaders of the Scottish National Party and Plaid Cymru; Ian Blackford and Liz Saville Roberts.

Other new MPs included; Chris Philp, Rebecca Long-Bailey, Angela Rayner, Antoinette Sandbach, Mhairi Black, Richard Burgon, Sue Hayman, Joanna Cherry, Oliver Dowden, Andrea Jenkyns, Suella Braverman, Chris Matheson, Amanda Milling, Heidi Allen, Stephen Kinnock, Jess Phillips, Ruth Smeeth, Kelly Tolhurst, Tulip Siddiq, Amanda Solloway, Craig Mackinlay, Alison Thewliss and Clive Lewis.

Below is a graphical representation of the House of Commons showing a comparison of party strengths as it was directly after the 2015 general election.

Directly after the 2015 State Opening of Parliament, the Speaker nominated Sir Roger Gale (Conservative, North Thanet) and George Howarth (Labour, Knowsley) for these positions.

[6] Although Deputy Speakers do not resign from their parties, they cease to vote (except to break ties) and they do not participate in party-political activity until the next election.