(CNN) — Chris Christie is getting outside legal help to deal with a scandal involving traffic gridlock as alleged political retribution.
The politically embattled New Jersey governor’s administration announced Thursday it retained a law firm to help conduct an internal review and cooperate with a U.S. attorney’s inquiry into the controversy that could harm Christie’s presidential ambitions.
Meanwhile, state Assemblyman John Wisniewski, the Democratic chairman of a special committee investigating the scandal, said he expects it to issue 10 to 20 subpoenas later in the day.
Also Thursday, the New Jersey Senate announced its own investigation in coordination with Wisniewski’s Assembly panel, widening the political response to the controversial closing of access lanes on the Jersey side of the George Washington Bridge that jammed traffic for four days in September.
Considered the front-runner for the GOP presidential nomination in 2016, Christie appeared to refer to the scandal when he told an event Thursday involving Superstorm Sandy recovery efforts that “no one, I can assure you, ever told me or anyone on my team that it was going to be easy.”
“Whatever test they put in front of me, I will meet those tests,” Christie said to applause.
Separately, a source close to Christie said the governor believes the investigations into the scandal will be a long process.
Christie does not intend to address the controversy in his inaugural address after he gets sworn in for a second term next week, the source told CNN’s Dana Bash on condition of not being identified.
Documents made public last week suggested that top staffers in Christie’s administration orchestrated the traffic logjam in Fort Lee as payback for the failure of the town’s Democratic mayor to endorse the governor for re-election.
Two sources told CNN on condition of not being identified that initial subpoenas would focus on documents.
The eventual subpoena list includes Christie’s former Deputy Chief of Staff Bridget Kelly, as well as the governor’s chief spokesman, Mike Drewniak, and Bill Stepien, a sharp-elbowed Christie political confidante who managed both his successful gubernatorial runs, according to the sources, who spoke on condition of not being identified.
Christie fired Kelly and asked Stepien to leave his political operation after last week’s release of explosive e-mails on the scandal.
The controversy involves the closing of two access lanes to the nation’s busiest bridge that caused gridlock in Fort Lee two months before Christie was re-elected as governor.
In response to questions from Democratic Sen. Jay Rockefeller, who chairs the Senate Commerce, Science and Transportation Committee, the Port Authority of New York and New Jersey said that a traffic study cited as the reason for the lane closures was an “aberrational” event conducted outside of normal protocol.
The response, based on testimony previously provided to the New Jersey State Assembly, said Christie’s appointee to the authority leadership, David Wildstein, ordered the lane closures and suggested that he failed to heed warnings about their impact.
In addition, Wildstein ordered a Port Authority manager “not to communicate information about the lane reduction” to officials in Fort Lee and indicated “he would control the communication about the toll lane closures,” according to the response.
Wildstein resigned from the Port Authority late last year as the controversy unfolded.
Despite polls showing Christie as the early favorite for the Republican presidential nomination two years from now, the bridge crisis has grabbed national attention and forced the normally combative governor to adopt a more conciliatory posture.
“Governor Christie made clear last week that he will conduct an internal review to uncover the facts surrounding the lane closures in Fort Lee,” his office said Thursday. “His administration is fully cooperating with the U.S. Attorney inquiry and other appropriate inquiries and requests for information.”
The Christie administration has retained Gibson, Dunn & Crutcher LLP as outside counsel in a move the administration hopes “will bring an outside, third party perspective to the situation.”
Randy Mastro, a former assistant U.S. attorney for the Southern District of New York, will head up the legal team.
Mastro has experience in organized crime cases and led the federal racketeering lawsuit that forced the International Brotherhood of Teamsters to hold democratic elections and to undergo court supervision. Mastro also is a former deputy mayor of New York City.
On the other side, the Democratic-led state Assembly panel investigating the scandal will be assisted by attorney Reid Schar, a key figure in the federal prosecution of former Illinois Gov. Rod Blagojevich.
U.S. Attorney Paul J. Fishman is also looking into the bridge matter, and the state Senate inquiry approved Thursday brings the total number of investigations to four, including the internal review by Christie’s office.
On Tuesday, Christie addressed the scandal briefly in his State of the State address, saying that “mistakes were clearly made.” He also tried to shift the focus to policy initiatives, repeatedly imploring Democrats to work with him.
At a nearly two-hour news conference last week, Christie forcefully denied that he was involved in or had any knowledge of what his aides may have been up to.
The allegation first made by Democrats was subsequently magnified by the e-mails that state legislators released last week.
Kelly’s name appeared in e-mails with Wildstein, including one in which she wrote: “Time for some traffic problems in Fort Lee.”
Other exchanges suggested that Stepien was aware of the maneuvering that led to traffic gridlock.
While the e-mails do not link governor’s spokesman Drewniak to the traffic jam scandal or even suggest it, they indicate that he had dinner with Wildstein two days before the transportation official resigned. Wildstein thanked Drewniak for his “sound advice,” and the two men later e-mailed back and forth about how to announce his departure from the Port Authority.
Federal officials also are looking at New Jersey’s use of $25 million in Superstorm Sandy relief funds for a marketing campaign promoting the Jersey Shore’s recovery that featured Christie and his family.
In a statement Monday, Christie’s office said the “Stronger than the Storm” campaign was part of an “action plan” approved by the Obama administration and developed with the goal of showing that the New Jersey Shore was open for business several months after the storm that devastated parts of the mid Atlantic in October 2012.
The campaign took place the same year that Christie was running for re-election.
On Tuesday, the federal Housing and Urban Development agency described the probe as a routine audit “and not an investigation of the procurement process.”
CNN’s Shimon Prokupecz, Ashley Killough, John King and Laura Koran contributed to this report.