London (AP) - Britain will make history by holding its first ever televised political debate for top candidates Thursday - a risky endeavor in this wildly unpredictable national election.
Thursday's debate will focus on domestic issues, while the televised 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 are painfully aware of the famous blunders that litter U.S.-presidential debate history - Richard Nixon's sweaty brow during his face-off with John F. Kennedy in 1960, Gerald Ford's mistake of saying Poland was not under Soviet control and Dan Quayle naively comparing himself to Kennedy.
Pollsters say half of the British electorate, some 20 million people, plan to watch Labour's Prime Minister Gordon Brown, Conservative leader David Cameron and Nick Clegg of the Liberal Democrats square off.
"This could be the thing that breaks the deadlock," said Robert Worcester, founder of the Ipsos MORI polling firm.
Each candidate has their own image problems, but they will be expected to come across as confident, knowledgeable, relaxed and sincere. Some 6 million swing votes are at stake.
Both Brown and Cameron have consulted experts from President Barack Obama's election campaign. Brown is advised by media guru Michael Sheehan and polling expert Joel Benenson. Cameron has tapped Obama's ex-communications director Anita Dunn, as well as two former presidents of the Oxford Union debating society.
Brown, 59, will need to convince the public that he is relaxed, authoritative and has more experience than his rivals and overcome his often-clumsy, disheveled appearance on screen. But because expectations are low for him, even a moderate performance could be seen as a win.
The 43-year-old Cameron needs to overcome his image as a posh politician disconnected from the working class and back up his ideas with substance and detail.
Articulate, privileged and married to an aristocrat's daughter, Cameron has tried to seduce voters with the idea that the party once led by Margaret Thatcher is more compassionate today. Often compared to the charismatic Tony Blair, who brought the Labour Party back to power 13 years ago, Cameron is often seen cycling or doing Web cams of his family life.
But it's unclear whether his folksy "Just call me Dave" campaign or his pregnant wife's visits to soup kitchens have convinced a dubious electorate.
For Nick Clegg, 43, the debate has automatically boosted his third-place Liberal Democrats. Advisers say Clegg will need to rein in his temper and convince the electorate that he has what it takes to be prime minister.
The election is the closest Britain has seen in years. Political parties are barred from paid television ads in Britain, which makes the debates even more resonant. Any mistakes and glories will be repeatedly broadcast on YouTube and over the Internet.
"It breaks new ground in British politics and for that reason it's a very, very interesting day," Health Secretary Andy Burnham, a Labour lawmaker, told GMTV television.
Some 76 guidelines govern the live 90-minute debates, 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 must stay quiet. Leaders won't know the questions in advance and won't be able to confront one another directly.
A ComRes poll found 31 percent of respondents said they wouldn't watch the debate, and of those that will tune in, only half believed it would have any influence on their ballot. The survey of 1,001 adults April 12-13 had a margin or error of plus or minus 3 percentage points.
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.
Associated Press Writers Gregory Katz and David Stringer contributed to this report.
Britain will make history by holding its first ever televised political debate for top candidates Thursday - a risky endeavor in this wildly unpredictable national election.