British Prime Minister Tony Blair chose a new foreign secretary Friday and fired his home secretary in a wide-ranging Cabinet reshuffle after his party suffered a heavy defeat in local authority elections. Blair initiated the shake-up after his Labour Party ran an embarrassing third in English elections Thursday - a result that prompted renewed calls from some quarters for the prime minister to step down. Blair removed Jack Straw as foreign secretary, replacing him with Margaret Beckett, who had headed the Department of Environment, Food and Rural Affairs. There had long been rumors of tension between Straw and Blair - some reports said the outgoing foreign secretary had privately expressed doubts about the Iraq war, and he publicly took a different stance on Iran than Blair did. Straw described military action against Tehran as "inconceivable" and alleged US contingency plans for a tactical nuclear strike as "nuts," something neither the prime minister nor US leaders would say. Beckett's appointment as foreign secretary, the government's most internationally visible post after prime minister, came as a surprise. She is an experienced politician and loyal to Blair but has little experience in foreign affairs beyond her participation in international climate change talks. Beckett becomes the first woman to hold the job. Home Secretary Charles Clarke, embroiled in a politically damaging furor over the failure to deport foreign criminals, confirmed Blair had removed him from office. Defense Secretary John Reid replaced Clarke, and Des Browne was promoted from chief secretary at the Treasury to secretary of defense. The shake-up appeared aimed at demonstrating Blair still holds a firm grip on his beleaguered government after weeks of negative headlines and scandal. "It's a last-ditch wielding of the last substantial piece of authority he has" - the power to hire and fire, said Martin Bright, political editor at the left-leaning New Statesman magazine. Straw becomes leader of the House of Commons and takes responsibility for overhauling the House of Lords and campaign finance reform, two big issues. In low turnout, Britain's Conservatives won 40 percent of the vote, compared to just 26 percent for Labour. Labour lost control of 16 local councils - including some boroughs in London - and the Tories gained eight. The far-right British National Party won 18 seats, a gain of 14.