In Pictures: UK votes for a hung Parliament
Britain today has a hung Parliament after an inconclusive result to the most tightly fought General Election in a generation.
With 36 seats still to be counted, David Cameron's Conservatives had secured 289 MPs - making it impossible for them to reach the 326 threshold for an overall majority.
The results set the scene for behind-the-scenes horse-trading possibly stretching into the weekend and beyond, as the parties struggle to form a viable administration.
Mr Cameron is now expected to pile on pressure for Mr Brown to concede defeat and clear the way for him to try to govern, either at the head of a minority administration or with the support of Northern Irish unionists and other parties.
Speaking at the Witney count, Mr Cameron said: "What's clear from these results is that the country, our country, wants change. That change is going to require new leadership and we will stand ready to do all we can to help bring that leadership."
Foreshadowing extensive wrangling over who would form an administration, Mr Cameron promised to put the national interest first in the "hours ahead, or perhaps longer than the hours ahead".
A rollercoaster night may not have produced a clear result, but it did deliver some memorable moments, including the defeat of some of Westminster's big names.
High-profile casualties at the ballot box were former home secretary Jacqui Smith - who was an early casualty of the MPs' expenses scandal - ex-Cabinet heavyweight Charles Clarke and a clutch of junior ministers.
But Tories were denied their "Portillo moment" in Morley and Outwood, where Mr Brown's closest Cabinet ally - and possible successor - Ed Balls hung on with a majority of just over 1,000 despite a determined Conservative effort to "decapitate" him.
A handful of prominent Lib Dems lost their seats included Lembit Opik, ousted by a massive swing to the Conservatives in Montgomeryshire, and Susan Kramer, who lost to environmentalist millionaire Tory Zac Goldsmith in Richmond Park.
And in Northern Ireland, Democratic Unionist leader Peter Robinson - damaged by recent revelations about his wife's private life - sensationally lost his East Belfast seat to the city's lord mayor Naomi Long, who becomes the non-sectarian Alliance Party's first MP.
In Brighton Pavilion, Green leader Caroline Lucas became her party's first MP, telling cheering supporters that they had put "the politics of hope above the politics of fear".
But the British National Party failed to deliver the breakthrough it was hoping for, with leader Nick Griffin trailing in third place in Barking. Labour victor Margaret Hodge said voters in the east London seat had sent a clear message to the extreme-right party: "Pack your bags and go."
Election night was marred by chaos at polling stations across the country as hundreds of voters in areas including Sheffield, Hackney and Manchester tried in vain to cast their ballots before the 10pm deadline.
The Electoral Commission promised a thorough review.