10:14 p.m. EST February 18, 2014   ASBURY PARK, N.J. — A legal showdown is looming in the joint legislative investigation into the closing of the George Washington Bridge access lanes in September.

Bill Stepien, a key figure in the shutdown scandal and New Jersey Gov. Chris Christie's former campaign manager, is refusing to budge in the face of a subpoena from the New Jersey Legislative Select Committee on Investigation.

Stepien's attorney, Kevin Marino, sent a letter Tuesday to Reid Schar, the Chicago attorney hired by the committee, maintaining Stepien's earlier position. Stepien and Bridget Anne Kelly, Christie's former deputy chief of staff, have cited constitutional protections against self-incrimination and unreasonable search and seizure in refusing to turn over records.

"I can think of no lawful way the committee can obtain documents responsive to its subpoena from Mr. Stepien," Marino wrote. "Stated simply, his principled objections to the subpoena raise significant legal issues that are no less valid because they here arise in the context of a politically-charged investigation."

Tuesday was the deadline that both Kelly and Schar were given to respond.

Sen. Loretta Weinberg, the committee co-chair, said the committee probably will take the matter to court.

"I believe that would be our next move," she said.

The next meeting of the committee has not yet been scheduled, she said.

Kelly's attorney, Michael Critchley, said his position has not changed since he sent a letter Feb. 3 to the committee explaining why Kelly would not be responding to the subpoena.

"I feel the subpoena is constitutionally defective and my issues have not been addressed," he said Tuesday.

The committee voted along party lines Feb. 11 to reject Stepien and Kelly's legal arguments and to authorize Schar to set a new date for them to comply and to enforce the subpoenas, with eight Democrats deciding in favor and the four Republicans abstaining.

The committee fell short of holding Kelly and Stepien in contempt.

Asked for his response after the meeting, Critchley said, "That's why they have judges."

Marino said in the letter he also is set to go before a judge.

Marino wrote that Schar urged him to consider whether there were any materials responsive to the subpoena "for which his objections could be withdrawn" and offered to discuss that with Marino.

Marino rejected all Schar's points.

"Hence, I respectfully suggest that if the committee persists in its refusal to withdraw the subpoena, we confer an orderly process and schedule for seeking a judicial determination as to the validity of (Stepien's) objections," Marino wrote.

The committee has issued 19 subpoenas on top of the 20 that were initially sent out.