Polling stations are open across the country from 7am with voting taking place until 10pm on Thursday night
What time will we know who won? Guide to the nightConstituency finder and how boundaries have changed
It is the King’s duty as head of state to appoint a prime minister, and he is travelling from Scotland to Windsor Castle, ready to be on stand-by after being in Edinburgh for Holyrood Week.
The role is one of the few remaining personal prerogatives of the sovereign, because Charles does not act on advice nor need to consult anyone before doing so.
But the overriding requirement is to appoint someone who can command the confidence of the House of Commons – usually the leader of the party with an overall majority of seats in the Commons – to form a government.