President Donald Trump’s lawyers on Thursday took the next step in their fight to keep his financial records secret, formally asking the U.S. Supreme Court to review a U.S. House subpoena that a lower court in Washington found to be a lawful exercise of congressional oversight.

In Trump’s petition, his counsel William Consovoy, partner in Consovoy McCarthy, asked the justices to decide whether the House Committee has the constitutional and statutory authority to issue the subpoena.