This evening Brown, Cameron and Clegg will take part in the first ever televised party leaders' debates in the UK.
The general consensus is that a good performance is a gaffe-free performance.
However, things don't always go according to plan when the cameras are on during campaign season.
Face for radio
John McCain, the 72 year-old Republican candidate at the 2008 US presidential election was generally considered to have performed admirably in the third televised debate against Democrat candidate Barack Obama, but one split second moment made for television gold.
As he walked from the stage at the end of the exchange, McCain realised that he was heading in the wrong direction.
Whether in shock or to lighten the mood, McCain pulled a face that made for perfect front page fodder pitching an ice-cool Obama against a downright strange looking pensioner.
Sweating it out
Forever held up as a case study of why appearance matters is Richard Nixon's disastrous performance in his 1960 televised joust with John F Kennedy.
Listeners on the radio marked Nixon down as the clear winner, but in the unforgiving glare of the studio lighting Nixon, who was recovering from a bout of the flu, was shown to be unshaven, sweating and looking distinctly unwell.
Kennedy, in contrast tanned and healthy, couldn't stop smiling. Viewers declaring him the uncontested winner of the first televised presidential debate.
Repeat after me
After twice asking to start the interview afresh, Canadian candidate Stephane Dion thought he had nailed a particularly trying question.
"If you were prime minister now, what would you have done about the economy and this crisis that Mr. Harper has not done?" the Liberal candidate was asked in 2008.
Simple stuff, but in Dion's defence he claimed that English is not his first language and that he was suffering from a hearing affliction.
Broadcaster CTV news considered this an insufficient excuse, and after initially agreeing to ditch the first two takes, the producers decided to broadcast the full uncut disaster.
Conservative leader Stephen Harper seized on the footage as proof of Dion's economic incompetence, leading Dion to dismiss his opponents as having "no class and no plan." Maybe, but enough of a plan to win that October's election.
Stop, look, and listen
While not a TV debate as such, when David Cameron blundered badly in a televised Gay Times interview a few weeks ago the slip-up was making headlines within hours.
"I've tried to have free votes where possible on these sorts of issues but, er ... I'm responsible for votes here. Sorry, it's not a very good answer", Cameron explained when asked why his European MEPs had refused to support a motion condemning a homophobic law in Lithuania.
"If we vote for you, we want you to vote for us," the interviewer told Cameron.
"I do, I do," replied the Tory leader. "Do you know – can we stop for a second?"
Ok, so the footage appeared just a week before the campaign began in earnest, but as a collector's item it makes the cut.
Curtain call
Gerald Ford bamboozled his TV debate audience in 1976 when he boldly proclaimed: "There is no Soviet domination of Eastern Europe, and there never will be under a Ford Administration."
For would be-voters seeking a man of vision to take residence of the White House, Ford's inability to see the iron curtain ahead of him caused considerable concern.
New York Times Associate Editor Max Frankel, in the role of moderator, gave Ford a chance to dig himself out of trouble, but the Republican man instead declared communist Poland to be a fine example of an independent nation free of Soviet influence.
A few days later Ford burrowed deeper still, insisting: "I don't believe they [Poland] are going to be forever dominated—if they are—by the Soviet Union." The gap in his knowledge was too big for voters to ignore.
Watch out!
Slide back the sleeve, glance at your watch, and make it quite clear: you'd rather be somewhere – anywhere - else.
Perform the watch-check manouvre on camera, in front of a national television audience of millions, and you're really making the point.
In 1992, during a televised presidential debate with Bill Clinton, George H.W. Bush was caught checking the time as an audience member asked him how the economic downturn would affect his own presidential wallet.
"Of course, you feel it when you're president of the United States. That's why I'm trying to do something about it," Bush replied unconvincingly.
The defeated Bush later admitted what he was really thinking: "Only 10 more minutes of this crap." It showed.
Taxing questions
Many Lib Dems believe that their former camera-happy leader Charles Kennedy would have been a natural if given the chance to take part in a televised political debate.
However, one of the more frequently played clips of the 2005 general election campaign featured a bleary-eyed Kennedy struggling to answer questions on the party's tax policies as he launched that year's election manifesto.
It didn't look good. "Quite clearly, I did not convey it properly. It may be something to do with the fact I'm a bit short of sleep" Kennedy commented, a reference to the birth his son Donald just a week previously.
However, the footage was cited as evidence of Kennedy's alleged alcohol problems, a key factor as his party forced his resignation following the election.
Dimension jump
Harold Macmillan always looked like a politician more suited to an age before the cameras began to roll.
Still, the Conservative leader practised hard, and in his debut performance in 1955 he took with him a giant pig to make his point. Why?
The piggy bank was meant to demonstrate the difference in size of personal savings achieved under a Labour or Tory government, with one 30 times as large as the other.
However, the porcine designers forgot the simple mathematical act of cubing, leaving Macmillan holding a pig 27,000 times larger than it should have been.
Turner framed
In turning on his opponent's alleged plans for patronage in his political appointments, Liberal Party leader John Turner chose a terrible line of attack during the televised leader's debate in Canada's 1984 election.
Brian Mulroney, the Conservative leader, probably couldn't believe his luck, answering with a demand that Turner himself apologise for approving the "horrible appointments" of former Liberal leader Pierre Trudeau.
In almost sotto voce, Turner insisted that he "had no option" but to approve Trudeau's parting demands.
"You had an option sir," Malroney confidently replied. "To say 'no' – and you chose to say 'yes' to the old attitudes and the old stories of the Liberal Party."
Turner's panicked repeat of his "no option excuse" was a defining campaign moment and Malroney, swept into power, was soon able to make all the patronage appointments he wanted.
Charm: Offensive
Making it through a gaffe-themed top ten with no mention of George W. Bush is some achievement, but to leave out Silvio Berlusconi is an impossible task.
Our pick comes from a TV appearance during Italy's 2008 election.
Asked by a female member of the audience how he could help her to afford a mortgage, the famously roving eyes of Berlusconi widened. "You should perhaps look to marry a millionaire, like my son, or someone who doesn't have such problems," leered Berlusconi.
"With that smile of yours, you could even get away with it."
Much like Berlusconi does, time and time again.
This article first appeared in The House Magazine.
