THE exit poll which surprised many came out at 10pm and was the result of a day’s worth of polling station surveys.
To put together an exit poll researchers for the joint broadcasters approach voters as they leave polling stations and ask them to fill in a mock ballot paper to indicate how they have just voted.
Researchers are sent to around 140 polling stations across the UK, stations thought to be representative of their overall constituency.
Data is sent back to a secret room throughout the day, with the last piece coming in at 9.15.
It is illegal to publish the results prior to polling booths closing at 10pm.
The poll is carried out by polling companies NOP/Mori for the BBC/ITV News/Sky News.