The government has set up a "Brexit unit" to develop a plan for the UK's arduous negotiations with the EU.
The team will be made up of civil servants from across Whitehall and will present options to the cabinet about how the government can respond to last week's historic vote.
Oliver Letwin will play a "facilitative role" for the project, which will see civil servants to liaise with devolved authorities in Scotland, Northern Ireland and Wales.
Downing Street has not yet set out the names of any leaders of the project, or the numbers of staff involved.
The unit will consist of officials from the Treasury, Foreign Office and other departments.
However, it will not take any decisions on the UK's negotiating stance.
Brexit Britain: What you need to know
The announcement was made at the first cabinet meeting following the referendum as speculation over who will succeed Cameron continues to build.
George Osborne refused to say whether he will be a candidate, but Boris Johnson has reportedly already building his campaign team. There has still been no word from the home secretary Theresa May - expected to be one of Johnson's key rivals.