The opposition Conservative Party's Boris Johnson unseated Ken Livingstone on Friday to become London's new mayor, election officials said.

The result is a heavy blow to Prime Minister Gordon Brown's Labor Party and a huge boost to the Conservatives, who have not held a high-profile national post since being defeated by Tony Blair-led Labor in the 1997 national election.

"I do hope that it does show that the Conservatives have changed into a party that can again be trusted," Johnson said shortly after his victory.

Johnson, a former editor of The Spectator, is expected to take charge of a budget of 11 billion pounds (22 billion U.S. dollars) for the city with a population of some 7.5 million.

Issues he will have to address include a housing shortage, global warming, a much-maligned transport system as well as preparations for the 2012 Olympic Games.

"Let's get cracking tomorrow and let's have a drink tonight," Johnson said, adding that he will step down as a House of Commons lawmaker as soon as possible.

Meanwhile, Livingstone, who ran London for eight years, tried to confine the blame to himself rather than implicate Brown.

"The fault ... is solely my own. ... I accept that responsibility and I regret that I couldn't take you (Labor) to victory," he said.

Analysts attributed Labor's failure to grave concerns among voters over rising food and energy prices, higher mortgages and a possible housing market slump.

The victory of Johnson, 43, is likely to boost Conservatives' chances in the mid-2010 national election.

The win in London followed Conservative gains in local councils across England and Wales in elections on Thursday.

Conservatives took 44 percent of the vote in England and Wales, 20 points ahead of Labor, reported BBC.

Conservative leader David Cameron is widely considered one of the candidates to contest Brown for the premiership in 2010.

"Three years ago, the idea that the Conservatives would win London and build up a 20-point lead across the county would have been literally unthinkable," Cameron said.

(Xinhua News Agency May 3, 2008)