The man accused of buying the rifles a husband and wife used to kill 14 people in the San Bernardino terrorist attack in 2015 will ask to withdraw his guilty plea.

Enrique Marquez's lawyer submitted papers Wednesday with the federal court in Riverside saying his client will file a motion under seal to withdraw a 2017 guilty plea to providing material support to terrorists.

Prosecutors are expected to challenge the request. It was not immediately possible to determine whether the motion has been filed.

Defense attorney John Aquilina, who previously told the court he expected to file the motion by next Tuesday, didn't immediately reply to email and phone messages seeking comment.

Authorities say Marquez acknowledged buying the semi-automatic rifles that Syed Rizwan Farook and Tashfeen Malik used to attack a gathering of San Bernardino County employees on Dec. 2, 2015. The couple killed 14 people and wounded 22, then later died in a firefight with authorities.

In court filings in 2015, authorities said Marquez called 911 after the attack and said his neighbor carried out the shooting using a gun he had given him for storage.

Authorities said the FBI interviewed Marquez between Dec. 6, 2015, and Dec. 16, 2015, and that he waived his right to a lawyer when speaking with agents.

Marquez would face a potential 25-year prison sentence if the convictions stand.