WASHINGTON, April 23 (Reuters) - The U.S. Senate voted on Thursday to approve Loretta Lynch as President Barack Obama's next attorney general, ending a five-month deadlock that made Lynch wait longer for confirmation than the last seven attorneys general combined. The first black woman to become the top U.S. law enforcement official, Lynch, 55, was approved by a 56-43 vote. Ten Republicans voted for Lynch, including Senate Majority Leader Mitch McConnell. She is expected to take over as head of the U.S. Justice Department on Monday, replacing Eric Holder. The voting margin reflected many Republicans' disapproval of Lynch's support for an executive order issued by Obama in November that was meant to shield millions of undocumented immigrants from the threat of deportation. Before the vote, Republican Senator Jeff Sessions, an outspoken critic of that action, blasted Lynch. "We do not have to confirm someone to the highest law enforcement position in America if that someone is publicly committed to denigrating Congress, violating law," he said. Senate Democratic leader Harry Reid berated Republicans for delaying the confirmation and said Lynch was "as qualified a candidate" as he'd seen in almost 30 years in the Senate. Lynch has awaited confirmation since November when Obama, a fellow Harvard Law School graduate, nominated her. Despite the delay, she was widely seen as less controversial than Holder, who often clashed with Republicans. She has said she aims to smooth relations with Congress. As attorney general, her earliest tests will likely include handling civil rights cases stemming from deadly altercations between police and unarmed black men in several U.S. cities. The Justice Department has said it will look into bringing civil rights charges over the death of a Baltimore man who died after sustaining a spinal cord injury while in police custody. Lynch will also inherit major financial cases involving allegations that some of the world's largest banks helped clients evade U.S. taxes and manipulated the currency markets.