Washington: Presumptive Republican presidential nominee Donald Trump has dismissed his campaign manager as the New York billionaire was bogged down in controversies. "The Donald J. Trump Campaign for President, which has set a historic record in the Republican primary having received almost 14 million votes, on Monday announced that Corey Lewandowski will no longer be working with the campaign," Xinhua news agency cited a statement as saying. Lewandowski was in conflict with GOP officials at the Republican national committee. His competing relations with Trump's new campaign chairman Paul Manafort, an experienced presidential campaign advisor to many Republicans, was also a reason behind his dismissal, according to sources. Lewandowski's dismissal came at a time when Trump was ripped by both Democrats and Republicans after he made a series of controversial remarks, including his accusation that a Hispanic-American judge overseeing a civil fraud suit in California involving Trump University was biased.