LONDON - A poll in Britain revealed on Friday that British Prime Minister Tony Blair is less popular than his main rival for the first time in 12 years.

Blair also suffered more bad news on the electoral front, with results from by-elections for two vacant parliamentary seats yielding a poor showing for his Labour Party.

Pollsters YouGov, in a survey commissioned by the Daily Telegraph newspaper, found 30 percent of Britons thought new Conservative Party leader David Cameron would make the best prime minister, against 28 percent who preferred Blair.

The Telegraph said it was the first time any of five successive Conservative leaders had been preferred to Blair since Blair took the helm of the Labour party in 1994 as opposition leader under Conservative Prime Minister John Major.

In the Welsh district of Blaenau Gwent, independent Dai Davies defeated a Labour candidate for parliament, thwarting Labour"s hopes of winning back one of its heartland seats, which Blair"s party lost at the last election last year.

The area had been safely held by Labour for years until Labour stalwart Peter Law quit the party and ran as an independent, refusing to step aside when Labour leaders said the party"s candidate must be a woman.

After Law died of cancer, Labour hoped to win the seat back, and dispatched high profile cabinet members to campaign there, to no avail.

Friday"s results also brought bad news for Cameron, who took over the Conservative leadership seven months ago.

A Conservative candidate nearly lost the seat of Bromley, scraping by with just a few hundred votes in a seat which had been held strongly by the Conservatives since 1945.

Labour placed an embarrassing fourth, with fewer than 2,000 votes, behind the fringe anti-European UK Independence Party.

CONSERVATIVE LEAD

According to the Daily Telegraph poll, 39 percent of respondents would vote Conservative if there were a general election tomorrow, against 33 percent who would vote Labour. That compares to 35 percent backing Labour in April, with 33 percent saying they would vote Conservative.

Blair, who led Labour to an unprecedented third consecutive general election victory last year, has pledged not to seek a fourth term. But a series of government scandals over sex, sleaze and mismanagement has led to calls for him to step down soon in favor of finance minister Gordon Brown.

Of those quizzed by YouGov, just 7 percent said Brown would make an excellent prime minister, while 31 percent said he would be pretty good and 25 percent said he would not be very good.

The poll also showed the Conservatives, whose reputation for economic competence was hit when the British pound crashed out of the European Exchange Rate Mechanism in 1992, catching up with Labour on the key question of economic management.

The survey showed both parties were equal at 31 percent on the question of which would run the economy best.