TV debate: Ninety minutes that could change Britain

Huge audience expected on night that could swing polls

Britain enters a new era of three-party politics tonight amid growing evidence that the first election television debates between Gordon Brown, David Cameron and Nick Clegg could make or break their general election prospects.

A ComRes survey for The Independent and ITV News found that 65 per cent of the adult public say they will watch the three debates – about 30 million people. Half of them say the contests could influence how they vote on 6 May, meaning that 15 million votes could be up for grabs.

Much of the attention has focused on the battle to be prime minister between Mr Brown and Mr Cameron. But with many voters undecided, the equal footing given to Mr Clegg will make the three 90-minute debates very different to the televised presidential contests which began in the United States 50 years ago.

It also gives the Liberal Democrats an unprecedented chance to reach a huge audience. "It's a great opportunity – but an even bigger risk," one party adviser said yesterday.

Mr Cameron arguably has the most to lose because he starts as the front-runner in the opinion polls and is widely regarded as a better television performer than Mr Brown.

As the parties indulged in mind games before the big set-piece, Labour played down expectations. David Miliband, the Foreign Secretary, told The Independent: "The debates are a good part of the election process. But there is no question that David Cameron goes into the debates as a slick operator on a natural medium, on his chosen turf. This is his strength, but this is 90 minutes, and it is incumbent on the discussion to get into the substance.

"His strategy is obviously to surf along the surface, but there's no question at all that he's playing on his natural turf – Gordon's substance is going to have to come through, but there's no question that Cameron goes into this debate with all the bookies and odds being stacked in his favour."

Senior Labour sources predicted that Mr Clegg would emerge as the winner because he is "new and unknown" and viewers would be surprised by him. But they predicted a poll boost for Mr Cameron and acknowledged his "superior communications skills". One Labour strategist said: "Cameron will be sharp and slick and therefore may appear to come off best but may be rather off-putting. Gordon will just be himself – solid. He knows what he's doing but he won't set the heather alight."

Mr Cameron is said to be "a bit tense". Aides claimed that his busy election schedule meant he had not spent as much time "prepping" for the debates as he had wanted. They said he is prepared for Mr Brown and Mr Clegg to gang up on him on some issues. They hope the Liberal Democrat leader will come under scrutiny, especially on the economy.

The first half of tonight's debate, to be screened at 8.30pm on ITV, will focus on domestic affairs such as education, health and welfare. The others, on the following two Thursdays, will open with questions on international affairs and the economy respectively.

According to ComRes, the biggest group of people (33 per cent) say they will watch the debates and are open to them influencing how they will vote. Another 32 per cent say they will tune in but their vote will not be influenced by the programmes. Some 31 per cent say they will not watch any of the debates.

Almost four in 10 (37 per cent) of those who decline to say how they will vote are open to persuasion by the debates – which highlights just how crucial the three programmes could prove. Some 37 per cent of those who do not regard themselves as a natural supporter of any party are also open to be influenced.

Women (36 per cent) are more likely to be influenced by the leaders' TV battles than men (28 per cent) when they vote. So are younger people. Some 37 per cent of 18-to-24-year-olds are open to be influenced, compared to only 21 per cent of those aged 65 and over.

ComRes found that Liberal Democrat supporters are most likely to be swayed by the debates; 42 per cent of them are open to persuasion, compared to 35 per cent of Tory supporters and 29 per cent for Labour.

According to ComRes, the Tories have a six-point lead over Labour, up one point on our poll published yesterday. However, Tory support slipped during the fieldwork carried out immediately after Mr Cameron launched his party's manifesto on Tuesday.

The Tories are on 35 per cent (down one point), Labour 29 per cent (down two points), the Liberal Democrats 21 per cent (up two) and other parties 15 per cent (up one). The number of people certain to vote has climbed to 65 per cent – comparatively high by recent standards.

All three leaders have taken advice from Democratic Party advisers with experience of the presidential debates in the United States, although the lessons from America were more about style and tone than the fine print of party policy. One such golden rule states: "Remember that the camera is on you all the time, not just when you're speaking."

Both Mr Brown and Mr Clegg have gone through several 90-minute "rehearsals" but Mr Cameron's "prepping" has involved shorter bursts.

The Liberal Democrats took it so seriously that David Laws, the party's schools spokesman, rehearsed for his rehearsals with Mr Clegg, when he played the part of Mr Cameron.

Mr Brown was played by Chris Huhne, the home affairs spokesman, whom Mr Clegg defeated to win the party leadership. "He knows Nick's strengths and weaknesses," said one insider.

Alastair Campbell, Tony Blair's former communications director, is said to have enjoyed playing Mr Cameron in Labour's rehearsals – a part he shared with Douglas Alexander, the party's election co-ordinator. "Alastair got quite aggressive at times," said one source.

Last night, Mr Brown received a welcome boost ahead of the debate after it emerged that a group of economists from around the world was preparing to publish a letter arguing that the Tory plan to cut public spending this year would plunge the "fragile" economy back into recession.

It is understood that the letter, signed by 58 economists, argues Mr Cameron's plan for cuts this year was "rash action" that could lead to job losses. A leaked version of the letter, published in the Telegraph, was signed by economists including Lord Layard, Lord Skidelsky, Lord Peston and Sir David Hendry.

The correspondence may finally act as a counter-weight to a letter signed by more than one hundred businessmen, which backed Mr Cameron's decision to oppose Labour's decision to increase National Insurance.

"At a time when recovery is delicate it could even affect confidence to the degree that we are tipped back into recession - with much larger job consequences," the letter states. "This is not the time for such a destabilising action. The recovery is still fragile. Only when the recovery is well under way, will it be safe to have extra cuts in government expenditure."

ComRes telephoned a random sample of 1,001 GB adults on 12-13 April 2010. Data were weighted to be representative of all GB adults. ComRes is a member of the British Polling Council and abides by its rules. Full tables at www.comres.co.uk

Anatomy of the debate

The format

The first 45 minutes will be on home affairs. If a major event breaks during the day, leaders can be asked for their reaction.

The three men have one minute to make an opening statement on the debate theme. Once the three statements are complete, the first question will be asked. The leaders are given one minute to answer each question and another minute to respond to the answers of their opponents before a "free debate" of up to four minutes at the discretion the host.

The second half of the programme is made up of general questions from the public, selected by an ITV panel.

Audience applause is restricted to the start and end of the programme to ensure there is no bias in favour of one leader and to avoid wasting time.

The lecterns

Designed to be high enough for the leaders to rest their hands on them, without obscuring their faces. There is nothing in the elaborate rules to prevent them bringing piles of notes for reference – which they can rest on the lecterns – but the audience might be more impressed if they speak without notes.

The host

Alastair Stewart, the moderator, will stand in front of the stage – though naturally he will face the three leaders rather than have his back to them. He is one of ITN's most experienced newscasters, who acted as an anchorman during its coverage of the last general election, five years ago. He has been co-presenter of ITN News at 6.30pm since August. The studio audience will be seated behind and to either side of him.

Illumination

The most noticeable element of the backdrop will be the illuminated tubes in party colours, corresponding to the line-up of leaders.

The refreshments

Testing, testing...

There is a microphone on each lectern, but the leaders may also have microphones attached to their lapels for more consistent sound quality.

Could Nick Clegg be left on the margins?

Nick Clegg, who will be on the left of the picture, is the contestant with nothing to lose, but there is the danger for him that the other two will be so busy answering each other, point by point, that the Liberal Democrat leader will be marginalised.

Centre ground

David Cameron has the centre spot. When the Chancellor and shadow Chancellors held a live television debate on Channel 4, the centre position was given to the Liberal Democrat Vince Cable. This worked to his advantage, as he came over as the reasonable man holding the ring between two antagonists.

Cameron is not, however, going to want to be holding the ring while Brown and Clegg argue across him, and may find that his central position is a disadvantage, because it could make him look like the odd man out. But if he plays it well, it will give the impression that he is the star and the others are the support cast.

Right-wing position

Gordon Brown will be standing on the right of the picture, as viewers see it. Officially, ITV is not saying why he was positioned there, but in his youth, Brown was blinded in the left eye in a rugby accident. Having David Cameron and Nick Clegg on his right means that they will not be out of his vision.

And off-stage ...

Weeks of careful planning have taken place to ensure that each of the three party leaders is battle-hardened for their 90-minute bout tonight. But, as the three men slug it out, there will be another intense battle raging that the viewers will not see. Away from the glare of the studio lights, senior figures from all three parties will be whispering into the ears of the assembled members of the media, all claiming victory for their man.

Activity in the so-called "spin room" will be furious as advisers push the case for their candidate, ensuring that journalists note every carefully planned line, every choreographed gesture and every hint of a slip by their rivals. While the last two debates will see all journalists and party spinners crammed into one room, the first outing presents the parties with a problem. Broadcasters and print media have been split between two venues, meaning they will have to rush between them to make sure reporters are left in no doubt about their view of the outcome.

The teams assembled for the spin operations read like a Who's Who of Britain's top political movers and shakers. The Tories will bring out their biggest hitters to ensure the operation goes as smoothly as possible. Andy Coulson, the party's director of communications, will be overseeing things personally. He will be aided by David Cameron's personal spokeswoman, Gabby Bertin. Both George Osborne and William Hague will also be around to assist.

For Labour, Lord Mandelson will again be cast in the role of spinner-in-chief. Douglas Alexander, who is again playing a central role in Gordon Brown's campaign, will also be present. Tony Blair will have a representative on hand: Matthew Doyle, now his press spokesman, is temporarily returning to his previous role in Labour's media team for the occasion.

The Liberal Democrats' team will be overseen by Jonny Oates, director of election communications, and Danny Alexander, Nick Clegg's chief of staff. They will be ably backed up by Chris Huhne, Vince Cable and Lord Ashdown. Mr Clegg's spokeswoman, Lena Pietsch, and head of media, Sean Kemp, will also be attempting to spin the exchanges in the party's favour.

Out of sight of both viewers and journalists, there are three green rooms where the advisers will be watching. In each room there will be a telephone. If at any point the advisers think their leader is being treated unfairly, they can call a senior editorial manager. If the manager thinks the complaint justified, it will be relayed to the producers, who will speak to Alastair Stewart through an ear piece.

Andy McSmith and Michael Savage

The TV debate: Who's tuning in?

65% of the adult public say they will watch the debates

65% say they will watch and are open to being influenced

36% of women say they are likely to be influenced compared to

28% of men

37% of people between 18 and 24 say they are open to influence compared to

21% of those aged 65 and over

Source: ComRes for The Independent and ITV News