Republican Representative Doug Collins, Ranking Member of the US House Judiciary Committee, submitted an amicus brief in the US District Court for the District of Columbia Thursday asserting that the Democrat-led impeachment inquiry has no legal basis.

In the brief, Collins is asking the court to deny the committee’s application for an order authorizing the release of certain secret grand jury materials, arguing that the investigation is “not an authorized impeachment proceeding.”

The brief states that while an impeachment inquiry authorized by the full House of Representatives would fall under Federal Rule of Criminal Procedure 6(e)‘s judicial proceeding exception, the problem here is that House has not explicitly delegated the authority to conduct a formal impeachment proceeding to the committee. Historically, the committee “has never reported articles of impeachment against a president without first conducting an impeachment proceeding authorized by a full House vote.” The brief explained that without such vote, the Committee is merely conducting ordinary legislative oversight under House Rule X to determine whether an impeachment inquiry may be warranted in the future.

In addition, the brief also argues that the committee has not shown “a compelling need for the grand jury information it requests” because there are other ways to obtain the information, and a “particularized need to pierce the well-established policy of grand jury secrecy.” Collins also argues that the committee has failed to explain why the specific information it requested is connected to the purported rationale for conducting the proceeding.