Gordon Brown was Sunday installed as the new leader of Britain's ruling Labour Party, three days before he is due to take over as prime minister from outgoing Tony Blair. Brown, 56, was declared Labour leader at a special party conference in Manchester, northern England. He had no challenger for the leadership post, which meant that there was no vote, dpe reported. Earlier, the conference elected Harriet Harman, a high-powered lawyer and secretary of state for justice, as deputy party leader. Harmann, also 56, who has managed to keep her loyalty divided between Blair and Brown over the years, has recently said she regretted her vote for the Iraq war in 2003 and demanded that Britain should "apologize" for going to war with Iraq. Brown is due to take over as prime minister from Blair on Wednesday. Blair, who has led Labour since 1994, and became prime minister in 1997, introduced Brown as his successor to the conference, after a seven-week handover process. Blair announced on May 10 that he would step down as party leader and prime minister on June 27, after 10 years in power.