The exit poll has suggested the Conservatives could fail to win an outright majority in today’s crunch vote...and that could mean a hung parliament.
But exactly what is a hung parliament and what would it mean.
Will the party with the most MPs form the next government?
Not necessarily. The party with the most MPs, when the votes have been counted in all 650 constituencies, is normally described as the winner and its leader nearly always goes on to become the next prime minister.
But that might not happen if there is an inconclusive result. It is possible for the party that came second to form a government with the help of other parties.
How does someone win the election?
The easiest way to become prime minister is to win what is called a majority in the House of Commons - a majority is where your party has more MPs than all the other parties put together.
How many MPs do you need to form a majority?
The finishing line is 326. That would be enough for a government to vote through new laws without being defeated by their opponents. If they don’t reach that number we have got what is called a hung Parliament.
What is a hung Parliament?
When no single party can get enough MPs to form a majority on its own the Parliament is said to be “hung”. This happened at the 2010 general election.
What happens if there is another hung Parliament?
In a hung parliament, the incumbent PM stays in office - and lives in Downing Street - until it is decided who will attempt to form a new government.
There will be another frenzied round of talks between the party leaders and their negotiating teams, as they try to put together another coalition government or a looser deal to put either Conservative leader Theresa May or Labour leader Jeremy Corbyn (the only two people with a realistic chance) into power as prime minister in 10 Downing Street.
Or one of the two party leaders could opt to go it alone and try to run a minority government, relying on the support of smaller parties when needed to get their laws passed.