The state's highest court on Thursday tossed out a challenge to New York City Mayor Bill de Blasio's designation on the left-leaning Working Families Party line.

Both the state Supreme Court and the Appellate Division dismissed the challenge brought by the Manhattan Republican Party political director, Robert Morgan. Morgan argued that the Working Families Party didn't meet the requirements established by state election law, which allows political parties to give its party line to those who aren't members. The lower courts dismissed the case earlier this month saying that the petitioners failed to name the executive board of the party as a respondent.

“Petitioners brought this proceeding to challenge the Working Families Party's designation of Bill de Blasio as a candidate in its primary election for mayor of the city of New York,” according to the court's per curiam decision in Matter of Morgan v. de Blasio, 131. “They contend that the designating petition is defective because the executive board failed to comply with the restrictions on designating and nominating candidates provided for in Election Law.”