It’s almost 50 years since a fresh-faced and composed John F. Kennedy trumped Republican rival Richard Nixon in the first live televised debate between two U.S. presidential candidates. Nixon is remembered more for the sweat on his upper lip and his five o’clock shadow than for his answers in that 1960 debate.

The debate marked the beginning of the television era for political leaders – making the contest as much about image, poise and personality as about policy.

In that light, the call on Friday by three of Britain’s leading broadcasters – the BBC, Sky News and ITV – for the country’s political leaders to take part in a series of televised debates ahead of the general election has raised the political temperature for Prime Minister Gordon Brown.

Sky News has spearheaded a campaign for U.S.-style debates between Brown and opposition rivals David Cameron and Nick Clegg. While the Conservative party leader David Cameron and Liberal Democrats leader Nick Clegg have backed the idea, Brown has remained non committal.

The danger for Downing Street is that the longer they wait to endorse the idea, the more nervous Brown looks about taking on his younger rivals on television.

Does the ghost of Richard Nixon’s first live TV debate against Kennedy haunt the spin doctors at 10 Downing Street?