The Senate on Thursday night approved a resolution allowing Sen. John Ensign’s aides to testify before a grand jury investigating events surrounding the Nevada Republican’s affair with a former aide.

In a floor statement Thursday night, Majority Leader Harry Reid (D-Nev.) explained that the resolution would allow Ensign’s staff to testify before the grand jury and that Ensign has indicated he wants to fully cooperate with authorities.

“This resolution would authorize employees in the office of Sen. John Ensign to respond to subpoenas or requests for testimony by a federal grand jury convened in the District of Columbia to investigate matters relating to Sen. Ensign,” Reid said. “The Senator would like to cooperate with this request. This resolution would authorize the Senator’s staff to testify in these or related proceedings, except where a privilege should be asserted.”

The Department of Justice is looking into Ensign’s relationship with former campaign aide Cynthia Hampton and allegations that Ensign helped secure lobbying clients for her husband, Doug Hampton, who also formerly worked for Ensign. Ensign and Cynthia Hampton carried on an affair for months while the Hamptons worked for the Senator.

After learning of the relationship, Doug Hampton left Ensign’s office to work as a lobbyist. Hampton has alleged that Ensign actively sought to help him recruit clients, a charge that Ensign has denied.

Earlier this month, Sen. Tom Coburn (R-Okla.) — who lived with Ensign while the extramarital affair took place — acknowledged turning over thousands of pages of documents to federal investigators.