Mayor Ed Murray has resigned in the wake of a fifth allegation of sex abuse, this time from his cousin.

Murray denies the claims, but said that he was afraid the claims could impact city business. The resignation goes into effect at 5 p.m. on Sept. 13.

While the allegations against me are not true, it is important that my personal issues do not affect the ability of our City government to conduct the public’s business,” he said in a statement.

The Seattle Times broke a story today that one of Murray’s cousins alleged the mayor had engaged him in an unwilling sexual relationship when they were both teenagers in New York.

Four other men, all with criminal and drug histories, claimed Murray molested them or had sex with them while they were troubled teenagers. Murray has denied the claims, some of which happened while he was working for a youth center in Portland in the 1970s.

Murray tried to remind the city of his accomplishments.

“I’m proud of all that I have accomplished over my 19 years in the Legislature, where I was able to pass what were at the time the largest transportation packages in state history, a landmark gay civil rights bill and a historic marriage equality bill,” he said. “And I am proud of what we have accomplished together at the City during my time as mayor, passing a nation-leading $15 minimum wage, and major progressive housing affordability and police accountability legislation, as well as negotiating an agreement to build a world-class arena that I believe in time will bring the NHL and NBA to Seattle.”

Jeff Simpson, Murray’s former foster child, led the charge of allegations against the mayor, claiming that while in Murray’s custody in 1984, he was molested.

Members of Seattle City Council asked in July for Murray’s resignation.

Murray ended his statement with an apology.

But it has also become clear to me that in light of the latest news reports it is best for the city if I step aside, he said. “To the people of this special city and to my dedicated staff, I am sorry for this painful situation.

Seattle City Council President Bruce Harrell will become mayor and has five days to decide if he wants to complete the rest of Murray’s term. Director of Operations Fred Podesta has been tasked with leading the transition.