Initial polls handed a surprising victory to the third place Liberal Democrats' Nick Clegg. The 43-year-old looked relaxed with his hand resting in his pocket. He also spoke confidently and passionately – often looking intently into the camera or to the audience – about topics ranging from immigration to greed in the banking industry. Some bookmakers last week thought Clegg would be the worst performer in the first debate and the first to sweat.
A ComRes poll said 43 percent of the people thought Clegg was the clear winner; 26 percent thought the Conservatives' David Cameron won and 20 percent thought Labour's Prime Minister Gordon Brown won. There was some 11 percent who thought there was no clear winner. ComRes sampled some 4,032 people by telephone immediately after the debate for ITV News. No margin of error was given, but in samples of a similar size there is plus or minus of less than two percentage points.
A Populus poll for The Times showed 61 percent of the respondents gave Clegg the victory, while 22 percent said they thought Cameron won and 17 percent thought Brown won. The sample size was more than 1,000 people with a margin of error of plus or minus 3 percentage points.
One audience member in the debate described Clegg as the "Barack Obama of British politics."
The British prime ministerial debate – the first of three – was more subdued than US presidential debates or even the vicious exchanges often seen in Parliament. An estimated 20 million tuned in to see the candidates inside a Manchester studio.
Swing votes will be crucial in this election. A Populus poll for the Times newspaper showed the Labour Party closing in on the Conservatives. The poll gave the Conservatives 36 percent – a drop of 3 percentage points – to Labour's 33 percent. The Liberal Democrats had 21 percent. The margin of error was 2.5 percentage points.
Many polls say that because the election is so close that no party may win an outright majority in Parliament. If that happens, it will be the first time since 1974 that Britain has seen a hung Parliament. If there is a hung Parliament, that could prompt yet another election this year.
An estimated 6 million swing votes are at stake.
Audience members in Thursday's debate asked questions about immigration, health care, pensioners, the economy and the armed forces.
But the question that seemed to resonate most with the audience and the candidates was over the expense scandal last year that exposed lawmakers of all three main political parties for submitting claims for everything from pornography to country estate chandeliers.
Many voters have said they have been disgusted by politics since the expense scandal that began unraveling as Britain sunk deeper into economic turmoil.
Clegg responded to the question about what parties would do to clean up politics with a zinger – calling for an overhaul of Britain's political system and accusing Cameron's party of protecting Conservative donor Lord Ashcroft, a Belize-based billionaire who has funded the party for more than a decade. Donations are under investigation by the Electoral Commission since allegations that the company was not eligible to give money because it was based abroad with no direct UK connection.
"There are still people who haven't taken full responsibility for some of the biggest abuses of the system," said Clegg.
Clegg's remarks also seemed pointed at Cameron's social class – the 43-year-old Cameron comes from a privileged family and is married to an aristocrat's daughter. Since he took the reigns of the Conservative Party, he has been trying to convince voters with the idea that the party once led by Margaret Thatcher is more compassionate and inclusive today.
In the beginning of the debates, however, Cameron tried to answer a question about what he would do about immigration with a story about how he was talking about the topic recently with "a black man." It wasn't clear whether the anecdote referred to a black immigrant or a black Briton.
Cameron looked sandwiched between Clegg and Brown, appearing to get less air time than his two rivals.
He often clashed with Clegg and Brown, saying the current law and order system wasn't working properly."
"We are not seeing enough police on the street, we are not catching enough burglars, we are not convicting enough and, when we do convict them, they are not getting long enough sentences," said Cameron.
Many commentators said the rules of the debates were too rigid to produce spontaneous debate.
"There wasn't any dynamite – they stuck to party lines and knew that it was more about not making a mistake," said Victoria Honeyman, a lecturer in politics at the University of Leeds. She said it was understandable that Clegg topped instant opinion polls. "It's almost certainly because he's had exposure that he doesn't normally get," Honeyman said.
Analysts said Clegg looked like a nice guy, Brown the alpha male and Cameron the polished but anxious performer, according to Patrick O'Donnell, a social psychologist at the University of Glasgow.
"In terms of warmth, Clegg won by a mile. He was relaxed and made a lot of appeasement gestures to show he was on your side – the kind of person you would like to go for a pint with," O'Donnell said. "In terms of power, Brown won by a mile.
"If I was Cameron's backers I would be worried. He came across all the time as anxious and worried."
Brown, 59, needed to convince the public that he is relaxed, authoritative and has more experience than his rivals. He also needed to overcome his often-clumsy, disheveled appearance on screen, which he partially managed through occasional humor.
Because expectations were low for Brown, pollsters said his performance wasn't seen as a particularly damaging. Some even said he was impressive.
Looking relaxed and confident, Brown goaded Cameron over party funding and said his chief foe was failing to offer the public specifics on his plans to cut crime.
"This is not question time, it's answer time David," Brown quipped, referring to the raucous prime minister's question time in Parliament.
The next debates on April 22 and April 29 will focus on foreign policy issues and the economy, the most significant of all issues in the May 6 election.
The Labour Party, which has been in power for 13 years, only agreed to the debates after a bruising media campaign.
Candidates were painfully aware of the famous blunders that litter U.S.-presidential debate history – Richard Nixon's sweaty lip during his face-off with John F. Kennedy in 1960, Gerald Ford's mistake of saying Poland was not under Soviet control and former Vice President Dan Quayle naively comparing himself to Kennedy.
Both Brown and Cameron consulted experts from President Barack Obama's election campaign. Brown was advised by media guru Michael Sheehan and polling expert Joel Benenson. Cameron tapped Obama's ex-communications director Anita Dunn, as well as two former presidents of the Oxford Union debating society.
Some 76 guidelines governed the live 90-minute debate, a painstaking format to which all three parties finally agreed.
A panel of journalists chose questions for the leaders that will be asked directly by members of a 200-strong studio audience selected by pollster ICM. The audience was required to stay quiet. Leaders didn't know the questions in advance.
"This could be the thing that breaks the deadlock," said Robert Worcester, founder of the Ipsos MORI polling firm.
Jessica Leonard, a 27-year-old consultant thought the debates lived up to their expectations.
"As a voter in this country, I'm just really pleased to see them there on television – getting up there in front of us and showing their views ... ," she said. "A lot of people here feel they've been able to make character judgments they wouldn't have otherwise."
Associated Press Writers David Stringer and Helen Allman contributed to this report.