Steward Health Care's Ralph de la Torre, who is stepping down as the bankrupt private hospital network's chief executive, on Monday sued a U.S. Senate committee which has voted to hold him in contempt for refusing to testify about Steward's financial troubles.

De la Torre is asking the court to declare that all actions related to enforcement of the subpoena are invalid and unconstitutional — including the vote of the committee on Sept. 19 approving the criminal contempt resolution and its decision to present the resolution to the full Senate for a vote.