By William James
SALFORD, England, April 2 (Reuters) - The main TV debate of Britain's national election campaign yielded no clear winner on Thursday with three opinion polls producing four different winners, but David Cameron's attempt to appear the most statesman-like appeared to have paid off.
The event was staged less than six weeks before an unusually close national election on May 7 as polls continue to suggest Cameron's Conservatives and Ed Miliband's opposition Labor Party are neck-and-neck with neither on track to win a majority.
The results of three snap opinion polls released immediately afterwards underscored why the election - that will decide who governs Britain's $2.8 trillion economy - is being widely described as the closest and most unpredictable since the 1970s with voters naming no less than four winners.
One poll said Scottish nationalist leader Nicola Sturgeon had won, another said Labor's Miliband had narrowly triumphed, and a third said Cameron, Miliband and UK Independence Party leader (UKIP) Nigel Farage had come joint first.
None of the leaders managed to deliver a "killer line" that would set them apart from the other participants.
"There was clearly no knock-out blow," said Peter Kellner of pollster YouGov.
Jonny Tudor, 17, who asked the first question of the night, told Reuters afterwards: "I don't think there was a clear winner, each leader performed at different levels. Some performed well in answer to certain questions, other performed well on different subjects, but there was no definitive winner."
But in a result that will calm Conservative nerves, a Comres/ITV poll showed 40 percent of voters asked afterwards judged Cameron was the most capable of leading Britain, compared to 28 percent who named Miliband.
In an unusual format for Britain, Cameron faced off against six political rivals in what was the first and only full TV debate of a campaign that has yet to stir voters, many of whom say they feel jaded despite a rising economy.
'NO KNOCKOUT BLOW'
The ITV debate, held in a former pie factory near the northern city of Manchester, ranged across the economy, the health service and immigration in front of a strangely quiet studio audience.
It put leaders of traditionally fringe parties like UKIP and Natalie Bennett, the leader of the left-wing Green Party, on an equal footing with the Conservatives and Labor, who have dominated British politics for decades.
Sturgeon, the leader of Scotland's nationalists, joined Welsh nationalist leader Leanne Wood and Nick Clegg, the leader of the Liberal Democrats, the junior party in the country's coalition, to complete the lineup.
Cameron, whose personal ratings are higher than those of his rivals, came off badly from Britain's first televised election debates in 2010. Over the course of three such debates, strong performances by Clegg were credited with helping deprive the Conservatives of an outright victory.
This time, Cameron has successfully resisted pressure to take part in a head-to-head debate with Labor leader Miliband, not wanting to hand his main rival a chance to improve his low personal ratings.
Nor will he take part in a planned second pre-election debate, dubbed the 'challengers' debate', which will feature the five parties outside the current coalition government.
He and Miliband were last week subjected to separate but back-to-back question and answer sessions on TV. A snap opinion poll afterwards suggested Cameron had come off better, but later polls showed Miliband had exceeded expectations. (Writing by Andrew Osborn; Editing by Guy Faulconbridge)