Stunning opposition victories Friday in local elections shook the Conservative Party's 12-year grip on power and made it virtually impossible for the new prime minister, John Major, to call an early national election.

Battered Conservatives blamed their trouncing in local elections on the recession and on lingering displeasure over ex-Prime Minister Margaret Thatcher's failed attempt to impose a so-called poll tax to help finance local government.Major, 47, who hastily abandoned the tax after the party dumped Mrs. Thatcher in November, said the results were "quite disappointing."

"But I think there's a great deal to look forward to. . . . We are on an upswing and they have peaked," he told a television interview, referring to the main opposition Labor Party.

"The Liberals clearly did extremely well," Major said. "They did better than expected and I congratulate them for that."

With results declared in all 369 local councils at stake, a tally by Press Association, the British domestic news agency, showed the Conservatives lost 1,135 of the 5,153 seats they previously held. The party won 245 seats, making a net loss of 890 seats.

Labor, which held 3,213 seats before the election, won 708 and lost 218, for a net gain of 490 seats. The Liberal Democrats, who controlled 1,639 seats before the balloting, won 750 and lost 230, for a net gain of 520.

Labor gained 17 new councils - five from the Conservatives, 12 that no party had controlled - giving the party control of a total of 127 councils.

The Tories lost control of 42 of their 119 councils but gained control of three other councils that previously had lacked a majority party; the Liberal Democrats won control of 17 councils.

Dozens of councils, including in the Conservative heartlands of the prosperous south of England, were left with no party in control. Some seats were won by the environmentalist Greens and other minor parties.

The opposition drive into Conservative strongholds included the genteel coastal town of Eastbourne, which went to the Liberal Democrats, and the naval base of Plymouth, which swung socialist after 25 years of Tory control.

"It's a warning to the government not to take its heartlands for granted," said Treasury Secretary David Mellor.

In the industrial belt of central England, droves of skilled blue-collar workers who voted Conservative in the Thatcher decade of the '80s turned back to Labor. The socialist party's prizes there included the city of Nottingham.

The results of the voting for 12,255 seats on local councils appeared to end stymie any hopes Major had of following Thatcher's practice of calling a general election every four years - a year before the deadline - and winning.