Opposition parties surged ahead of the governing Conservative Party today in local elections that are seen as the first major test of Prime Minister John Major's popularity. Early returns from the local races in England and Wales dampened speculation the prime minister would risk calling a general election next month. Major has one year left in which to call a national parliamentary election. With results in from more than half the 369 councils, which have a total of 12,200 seats, a BBC computer analysis showed a 6.5 percent overall vote swing to Labor compared with the results in 1987 council elections. With results in from 150 councils, the Conservatives had lost control of 20, while Labor made a net gain of nine councils and the Liberal Democrats a net gain of 13. Some of the councils are not controlled by any one party. The results were based on a tally by the British news agency Press Association. Analysts had predicted gains by the socialist Labor Party, despite Major's abandonment of an unpopular local government tax that helped topple his predecessor, Margaret Thatcher, in November. But the upsurge for the centrist Liberal Democratic Party was a surprise. The swing in party loyalties was not expected to be big enough to put Labor in a position of power for a general election. Labor candidates captured Plymouth, a south England naval base which had been Tory territory for 25 years. "You can cast aside any idea of a June election," said Labor Party spokesman Bryan Gould. "We're making gains all over the country." Tory party chairman Chris Patten said the party had "a very steep hill to climb." There were no elections in London, Scotland and Northern Ireland.