LONDON -- The Conservatives captured the largest number of seats Thursday in Britain's national election but will fall short of a majority -- triggering uncertainty over who will form the next government, according to television projections based on exit polls.
An analysis by Britain's main television networks suggested David Cameron's Conservative party will win 307 House of Commons seats, short of the 326 seats needed for a majority.
Polls gave Prime Minister Gordon Brown's Labour Party 255 seats, and Nick Clegg's Liberal Democrats 59 seats -- far less than had been expected. Small parties got 29 other seats.
The result would bear out predictions that this election would not give any party a majority, resulting in a destabilizing period of political wrangling and uncertainty. Brown could resign if he feels the results have signaled he has lost his mandate to rule, or he could try to stay on as leader and seek a deal in which smaller parties would support him.
The parties immediately began jockeying for position.
Theresa May, a senior Conservative Party lawmaker, said the exit poll result showed Labour's heaviest losses since 1931, and that the incumbent party had lost "the legitimacy to govern."
But Labour's Business Secretary, Peter Mandelson, pointed out that the sitting prime minister is traditionally given the first chance to form a government.
"The rules are that if it's a hung Parliament, it's not the party with the largest number of seats that has first go, it's the government," he said. "I have no problem in principle in trying to supply this country with a stable government."
But he extended an olive branch to the Liberal Democrats, who have called to end the so-called first-past-the-post system, where the number of districts won -- not the popular vote -- determines who leads the country.
"There has to be electoral reform as a result of this election," Mandelson said. "First-past-the-post is on its last legs."
The results may yet change. Projecting elections based on exit polls is inherently risky -- particularly in an exceptionally close election like this one. Polls are based on samples -- in this case 18,000 respondents -- and always have some margin of error.
Britain's census is nine years out of date and the polling districts haven't caught up to population shifts. Many voters also refuse to respond to exit polls.
Thousands have also already cast postal ballots but those results don't factor into the exit polls. About 12 percent cast postal ballots in 2005.
The projection suggests that the Conservatives will gain 97 seats, Labour lose 94 and the Liberal Democrats lose three.
"I think we're going to see a very interesting night," Conservative Party chairman Eric Pickles said.
The Tories are hoping to regain power for the first time since 1997, when they were ousted by Labour under Tony Blair. After three leaders and three successive election defeats, the party selected Cameron, a fresh-faced, bicycle-riding graduate of Eton and Oxford who promised to modernize the party's fusty, right-wing image.
Whoever wins faces the daunting challenge of introducing big budget cuts to slash Britain's huge deficit.
The election result would be disastrous news for the Liberal Democrats, Britain's longtime third party, who enjoyed a big poll surge after charismatic leader Nick Clegg's appearance in televised TV debates. Under Britain's first-past-the-post electoral system, that failed to translate into gains on the 62 seats the party won at the last election in 2005.
Labour's deputy leader Harriet Harman told BBC News: "It's obviously going to be very close. What is clear is that the country is going to need a strong and stable government to take us through the recession."
Liberal Democrat deputy leader Vince Cable described the outcome of the exit poll as "very strange" and insisted they had been "horribly wrong" in the past.