* Lib Dem leader Clegg seen as winner in election debate

* Opposition party support rises 3 points nationally

LONDON, April 16 (Reuters) - Support for Britain’s Liberal Democrats jumped after a historic television debate in which the leader of the second-largest opposition party emerged as a clear winner with viewers, a poll for the programme said on Friday.

The ComRes survey for ITV News put national support for the Lib Dems up three points on 24 percent, behind the opposition Conservatives on 35 percent and ruling Labour on 28 percent ahead of an election on May 6.

It was the highest score for the LibDems in a ComRes poll since the last election in 2005.

The poll of 4,000 viewers was conducted immediately after the broadcast of Britain’s first televised election debate between the leaders of the main three parties. The results were adjusted to make them nationally representative.

If the ComRes result was repeated uniformly across Britain on polling day it would lead to a hung parliament with the Conservatives as the largest party, according to a results predictor on the Sky News website.

Surveys released after the ITV debate found Lib Dem leader Nick Clegg had found most favour amongst viewers.

Pollster YouGov said 51 percent of respondents thought Clegg performed best, ahead of Conservative leader David Cameron on 29 percent and Labour Prime Minster Gordon Brown on 19 percent.

Clegg has refused to say whether he would support a minority Labour or Conservative government after the election.

The Conservatives have led polls since January 2008, with the Lib Dems, who only hold 63 of parliament’s 646 seats, consistently in third place.

The Lib Dems polled 22 percent of the vote in the 2005 election, and their support has ranged around 20 percent in surveys conducted in the following five years. (Reporting by Tim Castle; Editing by Jon Boyle)