Prime Minister Margaret Thatcher said Friday she will press on with unpopular anti-inflationary policies despite her Conservative Party's most stunning by-election defeat in 50 years. ``We are not a fair-weather party. We are not for trimming and turning,'' Mrs. Thatcher said in a letter to party chairman Kenneth Baker after Thursday's upset. The letter was released by the party headquarters. The opposition Labor Party scored a landslide victory in the previous Tory stronghold of Mid-Staffordshire in central England. Labor leaders declared that 11 years after being ousted by Mrs. Thatcher, they are on course to return to power. In Mid-Straffordshire, Labor candidate Sylvia Heal, a social worker, took 49 percent of the vote. The Conservatives' Charles Prior got 33 percent, while other parties took the rest of the votes. The one-seat loss scarcely dented Mrs. Thatcher's control of the 650-member House of Commons, where she has an overall 100-seat majority. But the by-election rout raised new uncertainties about her political future. Recent straw polls have indicated a significant minority of the Tory members of the House of Commons _ who elect the party leader each fall _ want her to retire before the next election. It must be held by mid-1992. Her party and personal ratings are slumping largely because of soaring home loan rates and a new local tax, which will replace property taxes starting April 1 and increase what many Britons pay the government. Some senior Tories acknowledge the new tax, formally known as a community charge, has been a blunder. ``The government has got to be a lot more sensitive ... there have got to be changes in the community charge,'' said Tory legislator John Lee in a radio interview. Lee's north England district, Pendle, is among 76 highly vulnerable Tory constituencies held by majorities of few thousand votes or less. Labor Party leader Neil Kinnock said the victory Thursday was a turning point for the Conservatives, who ``are going to have to make up their minds how quickly they get rid of Mrs. Thatcher.'' ``Her leadership is misleadership, and the sooner she goes the better,'' he said on British Broadcasting Corp. TV. ``We will defeat any Conservative leader at the next election.'' The Conservatives, 10 points ahead in opinion polls a year ago, are now 21 points behind Labor. It is the biggest deficit since Mrs. Thatcher won a third consecutive term in 1987. Government popularity has waned steadily as the Thatcher administration doubled interest rates to 15 percent in less than two years to try to curb resurgent inflation. But inflation is more than 7 percent, among the highest of major industrialized nations. The government is banking on inflation to start falling next year in time to lower interest rates before it has to call an election.
