Senate Judiciary Chair Dick Durbin (D-Ill.) condemned conservative Supreme Court Justice Samuel Alito for criticizing lawmakers considering ethics reform for the high court.

Last month, Durbin’s committee approved a bill sponsored by Sen. Sheldon Whitehouse (D-R.I.) that would require the Supreme Court to follow a code of conduct and create a process to investigate potential violations. The bill now heads to the full Senate.

But on Friday, Alito told The Wall Street Journal that Congress should stop trying to pass such legislation, arguing that the Constitution does not give lawmakers “the authority to regulate the Supreme Court — period.”

“Justice Alito is providing speculative public commentary on a bill that is still going through the legislative process,” Durbin said in a statement on Wednesday. “Let’s be clear: Justice Alito is not the 101st member of the United States Senate. His intervention in Article I activity is unwise and unwelcome.”

Alito, alongside conservative Justice Clarence Thomas, has been embroiled in ethics controversies. The justice, who wrote the opinion that overturned the right to abortion established in Roe v. Wade, has been vocal in defense of his activities.

Alito and Thomas have both been accused of failing to formally report gifts on federal disclosure forms. ProPublica reported that Thomas for years accepted vacations, private jet travel, superyacht getaways and other largess from GOP megadonor Harlan Crow, and that Alito took a luxury fishing trip with a Republican billionaire who later had cases before the high court.

Alito responded to the ProPublica report with an op-ed in the Journal defending himself against the claims before the outlet even published its investigation. The allegations resulted in Senate Democrats taking action to require the Supreme Court to follow ethics standards similar to those in the congressional and executive branches.

“Ensuring ethical conduct by the justices is critical to the court’s legitimacy,” Durbin said. “The next time Justice Alito thinks about taking a private plane to a billionaire-funded fishing trip, he should have to ask more than, ‘Can I take this empty seat?’ He should have to ask if doing so is consistent with his legally-mandated ethical obligations”

Chief Justice John Roberts has said that ethics reform is not necessary, and that the court can be relied on to regulate itself. Alito went further, arguing Congress cannot apply any requirements on justices because the Supreme Court is an equal branch of government under the Constitution.

Congress already regulates how much the Supreme Court can spend annually. The Constitution says the Supreme Court’s jurisdiction as a court of appeals is subject to “such regulations as the Congress may make.”

“I’ve said from the beginning of this inquiry: if the court does not act on ethics reform, Congress will,” Durbin said. “We advanced a bill to do so last month, and we will continue our push to ensure that the highest court in America does not have the lowest ethical standards.”