Britain's treasury chief Gordon Brown replaces Tony Blair as leader of the governing Labour Party on Sunday, days before he is scheduled to take over as British prime minister after a decade in waiting. Brown can now set about proving to the fractured party and a disenchanted country that he can offer something different from what Blair gave in the 10 years he dominated British politics as premier. On Saturday, he warned he would not tolerate dissent from the party's manifesto. "There will have to be discipline in the government that I lead," he said. Blair's exit was reportedly hastened by the two men falling out over Blair's failure to make good on a previous agreement to step down after two terms and hand leadership over to Brown. The fallout led to an ugly last year in Blair's leadership marked by party infighting. But Brown now has the chance to put all that aside. On Sunday, he will be named party leader at a specially convened conference in the northern city of Manchester, and three days later will assume the prime minister's office. The 56-year-old Scot has a few years leading government before he faces what will likely be a tough battle in national elections in 2009 or 2010. He has been tainted by his support for the unpopular war in Iraq, and accused by former aides of having an autocratic management style. Brown has vowed to be his own man, but already has brushed aside suggestions he would loosen ties with US President George W. Bush - a point of disagreement among rank-and-file party members and large sections of the public who lambasted Blair as Bush's "poodle." "Any foreign policy that I manage or have responsibility for has got be about our national interest, but it is in our national interest that the prime minister of the United Kingdom has a good relationship with the president of the United States," Brown told British Broadcasting Corp. television. Sunday's conference will also hear the results of the party's deputy leadership election.