London (AP): Britain's Opposition Conservative Party leader David Cameron called Wednesday for live TV debates at election time, saying similar tussles in the U.S. have sparked interest among voters.

Cameron said debates between prospective presidential candidates had shown how live sparring on TV can capture the imagination of the electorate.

Democrats Hillary Clinton and Barack Obama clashed Tuesday evening in their latest televised exchange in the U.S. campaign.

``There is no doubt in the American elections that one of the reasons they have caught people's imagination is because night after night the contenders debate in live television debates,'' Cameron said.

Cameron challenged Prime Minister Gordon Brown to agree to debates during the next national election, due in 2009 or 2010. ``What on earth are you frightened of?'' the opposition chief taunted.

Opposition leaders commonly call for debates during elections, hoping to win a rare chance to verbally trip up a sitting leader on live TV.

Brown insisted debates are unnecessary, saying party leaders clash every week during sessions at the House of Commons.

Cameron urged the British leader to follow the example of the U.S., and recent election campaigns in Italy, Australia and Poland _ which all featured TV debates.

Of the weekly sparring session, Cameron told Brown: ``We have to be honest with ourselves _ not many people watch these exchanges and not all those that do are hugely impressed with them.''

In 2005, the leaders of Britain's three main parties did appear on one television program but not together. Appearing in sequence, they answered questions from the audience.