Viewers get ready for TV debate

About 21 million people are expected to tune into tonight's ITV debate

Almost half the electorate will be watching Gordon Brown, David Cameron and Nick Clegg in the UK's first live televised general election debate, according to two polls. Forty-two per cent believe Cameron will perform the best.

However, networks estimate there will be about 10 to 12 million viewers.

According to an ITN poll, half of expected viewers say the debate will influence their decision at the polls.

A Populus poll shows 42 per cent of respondents expect David Cameron to win, while 22 per cent think Brown will fare better. Only 10 per cent believe Nick Clegg will win.

Those advising the prime minister have told him that he needs to connect to the audience with emotions and not statistics, according the Guardian.

Alastair Campbell, aide to Brown, told the Fabian Review: "He's got the factual stuff in his head. But this is a very different format from prime minister's questions. It's television, it's historic, and the viewing figures are going to be huge. The rules make it quite an odd event - no applause and strict on timings, so it's about getting used to that format. I just get at him the whole time, the way that Cameron would."

Yet Labour and Conservatives worry the debate may tip in favour of Clegg.

The debate will start at 8.30pm tonight and last 90 minutes, with at least 45 minutes devoted to domestic issues.