NEWARK — The man who has admitted orchestrating the mysterious lane closings at the George Washington Bridge in 2013 testified on Tuesday that he was told that Gov. Chris Christie of New Jersey and Gov. Andrew M. Cuomo of New York had agreed to falsely explain the closings as part of a traffic study to try to “put an end” to a growing scandal surrounding them.

The confessed culprit, David Wildstein, testified that he had heard from two top Christie appointees at the Port Authority of New York and New Jersey, which operates the bridge, that the governors had hoped to stop the catastrophic traffic jams caused by the lane closings from hurting Mr. Christie’s re-election campaign.

Mr. Wildstein, who is cooperating with federal prosecutors in the trial of two former Christie aides accused of approving and directing the lane-closing scheme, agreed that Mr. Cuomo had told the Port Authority’s executive director to “stand down” from trying to publicly blame Mr. Christie and his aides for the closings, at least until Mr. Christie had won re-election in November 2013.

A spokesman for Mr. Cuomo issued a statement sternly denying that the governor and Mr. Christie had discussed a false story and denouncing Mr. Wildstein’s motivations.