Prime Minister Theresa May is to visit the Queen at Buckingham Palace on Wednesday to mark the dissolution of Parliament for the General Election.
Although MPs left Westminster on Thursday, Parliament does not officially dissolve until a minute after midnight on Wednesday morning, 25 working days before the June 8 poll.
Historically, a prime minister had to ask the monarch to dissolve Parliament. But the 2011 Fixed-Term Parliaments Act made the process automatic, removing the royal prerogative in the matter.
Mrs May is expected to be driven the short distance from 10 Downing Street to the Palace for a short audience with the Queen.
When Parliament is dissolved, every seat in the House of Commons becomes vacant and there are no MPs until a new Parliament is elected. However, Government ministers retain their roles and continue their work.
MPs are allowed access to Parliament for just a few days in which to remove papers from their offices, and facilities provided by the House of Commons are no longer available to them from 5pm on the day of dissolution.