LONDON - Prime Minister Tony Blair's Labor Party suffered a string of embarrassing election losses - including in Scotland, where the party was defeated for the first time in half a century - in what appeared yesterday to be a final rebuke to the departing leader.

Overall, Labor lost fewer seats than some expected, but the contest in Scotland - where Labor had won every election for 50 years - went to the Scottish National Party, which has pledged a referendum on independence by 2010 if it wins power.

"Scotland has changed for good and forever," said Scottish Nationalist leader Alex Salmond. "Never again will they say that the Labor Party has the divine right to rule Scotland. This is a historic election."

About 10,000 local council seats were contested in Thursday's vote in areas of England outside London. In Scotland, voters chose their local representation as well as the Scottish Parliament, which sits in Edinburgh and deals with Scotland-only issues. And in Wales, voters elected their national assembly, situated in Cardiff.

Blair, who is expected to formally announce next week that he will resign as prime minister, has claimed three national poll victories since 1997. Some activists concede the unpopular Iraq war and a domestic cash-for-honors scandal have made him a liability.

He said Labor's result was better than expected.

"You always take a hit in the midterm," he said, "but these results provide a perfectly good springboard to go on and win the next national election."

With results from 301 of 312 English councils counted, Labor lost 468 seats and control of eight councils, while the opposition Conservatives gained 859 seats and control of 38 more councils, to a total of 159.

In Scotland, the Scottish National Party took 47 of 129 seats, compared with 46 seats for Labor. The Conservative Party finished third, with 17 seats, while Britain's third main party, the Liberal Democrats, took 16.

Elections officials said they planned an investigation into tens of thousands of spoiled ballot papers in Scotland, fearing people may have been confused by a complex voting system.

Labor's performance marginally improved on results in 2006 local elections and was better than polls had suggested - though still among its worst-ever election performances.

Treasury chief Gordon Brown - Blair's likely successor - had cause for optimism, said Leighton Vaughan Williams, a political analyst at Nottingham Business School. "Margaret Thatcher's Tories used to suffer hellish beatings in midterm local polls in the 1980s," he said. "But every time, they stormed back to victory in national elections."