President Donald Trump’s longtime accounting firm must hand over eight years of his tax returns to New York prosecutors, a US appeals court ruled Monday in the latest setback for Trump in his tenacious efforts to keep his finances secret.

The ruling by the New York-based 2nd US Circuit Court of Appeals backed the ability of prosecutors to enforce a subpoena for the returns against accounting firm Mazars LLP. With the Republican president due to appeal, the ruling sets the stage for an expected showdown at the US Supreme Court, whose 5-4 conservative majority includes two justices appointed by Trump.

The office of Manhattan District Attorney Cyrus Vance, a Democrat, is seeking the returns as part of a criminal probe into Trump and his family real estate business. The scope of that probe is not publicly known.

Vance’s office has agreed not to enforce the subpoena while Trump petitions the Supreme Court. Under the agreement, Trump has 10 business days to file the petition. Trump, who built a real estate empire with his New York-based business before becoming president, also faces an impeachment inquiry in the Democratic-led US House of Representatives.