By Jonathan Stempel

(Reuters) - A federal judge refused to dismiss a criminal indictment against two former allies of New Jersey Republican Governor Chris Christie over their alleged roles in the 2013 George Washington Bridge lane-closing scandal, known as Bridgegate.

In a decision made public on Tuesday, U.S. District Judge Susan Wigenton, in Newark, New Jersey, rejected arguments by William Baroni and Bridget Anne Kelly that the laws under which they were charged were too vague and that they had no reason to know some of their activities might have been illegal.

Kelly, a former Christie deputy chief of staff, and Baroni, a former deputy executive director of the Port Authority of New York and New Jersey, were charged with wire fraud, civil rights deprivation and conspiracy for allegedly arranging the September 2013 shutdown of bridge access lanes in Fort Lee, New Jersey.

The closure led to several days of gridlock affecting the bridge, the world's busiest, which spans the Hudson River to connect New Jersey to Manhattan. Prosecutors said it was intended to punish Fort Lee's Democratic mayor for not endorsing Christie's successful reelection bid.

In her 23-page decision, Wigenton said reasonable public officials would understand that wrongdoing attributed to the defendants would violate drivers' right to travel.

"Political payback is not a significant government interest," she wrote.

Wigenton also said it was for jurors to decide whether to hold the defendants criminally responsible for their alleged dealings with former Port Authority executive David Wildstein, who pleaded guilty to conspiracy charges and is cooperating with prosecutors.

Michael Baldassare and Michael Critchley, lawyers who represent Baroni and Kelly respectively, did not immediately respond to requests for comment.

A trial is scheduled for Sept. 12, court records show.

Christie has not been charged and has denied involvement in wrongdoing, but the scandal hurt his popularity within New Jersey and weighed on his unsuccessful 2016 presidential run.

Both defendants are also seeking records from Christie's cellphone through subpoenas to a law firm that previously generated a taxpayer-funded report absolving the governor of wrongdoing. Critics of Christie have called that report biased.

Separately, a federal appeals court in Philadelphia is weighing requests by media to publicly release a list of unindicted co-conspirators. Oral arguments were heard on June 6.

The case is U.S. v. Baroni et al, U.S. District Court, District of New Jersey, No. 15-cr-00193.

(Reporting by Jonathan Stempel in New York; Editing by Leslie Adler)