Prior to the Fixed-Term Parliaments Act 2011, it was in the gift of the prime minister to call an early general election.
As a result of the legislation, introduced as part of the Conservative-Liberal Democrat coalition agreement, the process is no longer as straightforward.
A snap poll can now only be called when the government loses a confidence motion or when a two-thirds majority of MPs vote in favour.
This is 434 of the Commons’ 650 members.
Theresa May will table a Commons motion today calling for an election to be held on June 8.
This is expected to pass as both Labour and the Liberal Democrats have indicated they will support it.
After a short period to clear up outstanding bills, the Westminster Parliament will be dissolved.
This will take place on Wednesday May 3, 25 working days before polling.
That date will mark the start of the official campaign.
Voters will go to the polls on June 8, with the results expected in the early hours of the following day.
Theresa May has called for a snap election… So what happens next?
