Minutes after Gordon Brown left Downing Street, a few hundred yards away talks ended between Liberal Democrat and Tory negotiators on a future government.
Shadow foreign secretary William Hague said: "We now have some recommendations to take back to David Cameron and our parliamentary colleagues."
Lib Dem leader Nick Clegg's chief of staff Danny Alexander said that the talks had taken place in a "good atmosphere".
Mr Alexander added: "We are returning to report back to Nick Clegg and our parliamentary party."
The talks in the Cabinet Office had lasted five and a half hours.
The Lib Dems and Conservatives returned to talks at the Cabinet Office at around 2pm, and as the day wore on it appeared ever more likely that they would reach some sort of deal which would put Mr Cameron in 10 Downing Street at the head of a coalition government.