By Edith Honan
NEW YORK, Feb 3 (Reuters) - New Jersey lawmakers investigating a widening traffic scandal that threatens the political ambitions of Republican Governor Chris Christie said on Monday they had begun to receive some of the documents under subpoena for their probe.
A committee of lawmakers had issued the orders to a number of Christie's top aides, who faced a Monday deadline. The lawmakers did not give details of the documents they had received, and said in a statement that many people had been granted extensions "as is typical in such situations."
The lawmakers are investigating the September lane closures in Fort Lee, New Jersey, to the busy George Washington Bridge, which caused four days of traffic jams in the town across the river from New York City. The closures, which were ordered by Christie's aides, came after the Democratic mayor of Fort Lee declined to endorse Christie's re-election bid.
Christie, who is widely seen as a leading Republican candidate for the White House in 2016, has said he was unaware of his aides' actions and sacked his deputy chief of staff in connection with the lane closures. Still, the scandal has hurt his image and polls show him losing ground as a potential presidential contender.
The Democrat-controlled state legislature has served subpoenas on Christie appointees at the Port Authority of New York and New Jersey, which oversees the bridge, Christie's top aides and his re-election campaign.
The U.S. attorney for New Jersey also has opened an investigation into the traffic jam, which slowed school buses and emergency vehicles.
An aide served with a subpoena, Christie's director of intergovernmental affairs, Christina Renna, said on Sunday through her lawyer that she had resigned. In a statement, Renna said her departure was long planned so she could "pursue an opportunity in the private sector."
While Christie has not been directly implicated in the scandal, he has struggled to counter questions about his truthfulness and the tactics of his administration.
The Democratic mayor of Hoboken has said that people close to the governor withheld storm aid as a condition of the city supporting a development deal. The administration has denied the allegation.
Last week, David Wildstein, who personally oversaw the lane closures, told Port Authority that "evidence exists" Christie knew about the lane closures. Wildstein resigned from the Port Authority of New York and New Jersey late last year.
Wildstein offered no details, and over the weekend, Christie's office launched a counter-attack challenging his credibility.
"Bottom line -- David Wildstein will do and say anything to save David Wildstein," Christie's office said in an email to supporters.
Wildstein's lawyer did not immediately respond to a request for comment.
As Sunday's Super Bowl put New Jersey in the national spotlight, the Democratic National Committee launched an online video ad comparing Christie to a struggling football player.
"They say he's unstoppable ... unless he chokes," the ad intoned, juxtaposing football images with video clips of news coverage of Christie, before and after the scandal broke. "It's just the first quarter. It's going to be a long game."
Christie's approval rating among New Jersey voters, at 65 percent just before his re-election last year, has slid to 46 percent, a Rutgers-Eagleton Poll released last month showed.