The George Washington Bridge. | Drew Angerer/Getty Images

NEWARK, N.J. — Gov. Chris Christie’s former campaign manager — now a top aide to Donald Trump — was aware of the George Washington Bridge lane closures before they occurred and knew their intended purpose, according to the admitted mastermind of the political revenge scheme.

Former Christie ally David Wildstein said in federal court on Monday that he told the governor’s longtime lieutenant, Bill Stepien, about the idea of using local access lanes as a political “leverage point” months before they occurred. Stepien was a deputy chief of staff to the governor at the time.

The two discussed the concept again — that lanes would be closed to create a traffic jam and punish a local mayor — when the plan was about to be set in motion, said Wildstein, a secretive political operator and former schoolmate of Christie who was appointed by the governor to a position at the authority.

Stepien, by then the manager of Christie’s 2013 reelection campaign, asked about a cover story, Wildstein said.

“Mr. Stepien asked about what story we were going to use, and I told Mr. Stepien we were going to use the cover of a traffic study,” he said.

Stepien, who was hired this year as a national field director for Trump, has not been charged in the incident and had not been previously implicated.

Christie distanced himself from Stepien after details emerged about the scheme. While Christie is currently serving as the chairman of Trump’s transition team, he has said he did not have a role in Stepien’s hiring by the Trump campaign.

Wildstein, who was the director of interstate capital projects for the Port Authority of New York and New Jersey, told jurors in U.S. District Court on Monday that he first came up with the idea of closing some local lanes to the bridge six months before they occurred. The Port controls the bridge, considered to be the world’s busiest.

Wildstein, who has already pleaded guilty, said he visited the bridge in March 2013. It was the first time he got an overhead view of the upper level toll booths and spotted three local lanes leaving Fort Lee.

Wildstein said he thought right away about Fort Lee Mayor Mark Sokolich, a Democrat who was being courted for a possible endorsement of the governor’s reelection campaign.

“I noticed the traffic moving more quickly through those lanes, and I immediately thought this could be a potential leverage point with Mayor Sokolich down the road,” Wildstein said from the witness stand.

He said he told his then-boss, Port Authority Deputy Executive Director Bill Baroni, about what he saw and how the lanes could be used. Baroni was with him for the visit, he said.

“Mr. Baroni responded that he saw what I saw and he understood — he agreed with me — that this was a potential leverage point,” Wildstein said.

Wildstein later told Stepien, then a deputy chief of staff to the governor who ran the Office of Intergovernmental Affairs. After Stepien left to run the governor’s campaign later that spring, Wildstein told his replacement, Bridget Anne Kelly, about the idea.

Baroni and Kelly are both on trial for closing the lanes in what prosecutors say was an act of political retribution against Sokolich for refusing to endorse Christie. Both were indicted last May on charges of conspiracy, fraud and civil rights violations.

Kelly emailed Wildstein on the morning of August 13 to say it was “time for some traffic problems in Fort Lee.” Wildstein, who responded within a minute to say “got it,” said he immediately knew what she meant.

“I understand that to mean that it was time to change the lane configuration at the upper level of the George Washington Bridge in order to create traffic in the borough of Fort lee,” Wildstein told jurors under questioning by prosecutor Lee Cortes.

Wildstein said he spoke to Baroni that morning to say he heard from Kelly. He said they were both surprised she wanted to put the plan in place so late in the election season.

“Mr. Baroni was a little surprised it was coming in this late,” Wildstein said. “He asked how I was going to do that. I told him I was going to think about it and we’d talk about it later.”

Wildstein spoke to Kelly by phone at 5:48 p.m. that night.

“She told me the reason was to send Mayor Sokolich as message,” he said as Kelly, sitting on the opposite side of the court room, looked down. “The indication was that mayor Sokolich needed to fully understand that life would be more difficult for him in the second Christie term than it had been in the first.”

She later discussed with him that they wouldn’t have any communications with Fort Lee officials after the lane closures started, and that all complaints would be sent to Baroni’s office and not responded to. They called the approach “radio silence.”

“The purpose was to create as big a traffic jam as possible,” Wildstein said.

Wildstein said it was Baroni’s idea to close the lanes in September, not August. He said Baroni was concerned traffic might be much lighter with people on vacation and school out, and said Wildstein should figure out what day school started in Fort Lee. The answer, he informed Baroni, was Sept. 9.

“He smiled and said, ‘fantastic,’” Wildstein said.

Kelly also agreed, he said, and he went to work setting the scheme in motion.

Wildstein continued to testify Monday afternoon and could be on the stand for several more days.

Christie has denied any knowledge or involvement in the lane-closing incident. But Wildstein’s attorney says there is evidence to prove the governor knew about the plot when it was occurring, and prosecutors on Monday endorsed that theory, saying the governor was told of the traffic gridlock and the mayor’s unanswered complaints on the third day of the lane closings.