In a speech outside 10 Downing Street he said:
“The British people have voted to leave the EU and their will must be respected.
The will of the British people is an instruction that must be delivered.
There can be no doubt about the result.
Across the world people have been watching the choice that Britain has made.
This will require strong, determined and committed leadership.
I am very proud to have been Prime Minister of this country for six years.
I have held nothing back.
I think the country requires fresh leadership.
I do not think I can be the captain to take the country to its next destination.
In my view I think we should have a new prime minister in place by the start of the Conservative conference in October.”