WASHINGTON (AP) — The Trump administration says in a court filing that two dozen emails revealing details of President Donald Trump’s decision-making regarding withholding military assistance to Ukraine, which goes to the heart of his impeachment, are protected from a lawsuit under “presidential privilege.”

The existence of the 24 emails was acknowledged in a late Friday filing by the Justice Department in response to a lawsuit by the Center for Public Integrity that seeks the release of the emails without redaction. In December the nonprofit organization received heavily blacked out versions of the emails.

Heather Walsh, a lawyer for the White House Office of Management and Budget, told the court in the Friday filing that the emails “reflect communications by either the President, the Vice President, or the President’s immediate advisers regarding Presidential decision-making about the scope, duration, and purpose of the hold on military assistance to Ukraine.” Thus, she writes, the emails are privileged.

The filing was first reported by The Washington Post.

The two articles of impeachment that brought Trump to trial in the Senate stem from the president’s decision to withhold military aid to Ukraine. House Democrats allege that Trump abused his power by asking Ukraine to announce investigations of political rival Joe Biden and other Democrats in exchange for releasing the aid. House Democrats also charged Trump with obstruction of Congress for refusing to turn over documents and provide witnesses.

Trump has denied doing anything wrong, disputing that the aid was part of a “quid pro quo” for investigations and contending executive privilege shielded documents and advisers from testimony.

The legal team defending Trump in the Senate trial has argued that even if the aid were held up, Trump did so because of concerns of corruption in Ukraine. Additionally, the defense team has argued that even if Trump held up the aid for an investigation of a political rival, it would not amount to a valid reason for impeachment or for removal from office.

Senate Republicans voted Friday to deny Senate Democrats’ demands that new evidence and new witnesses be considered during the trial. A vote to convict or acquit Trump was expected Wednesday, with acquittal all but assured in the Republican-led chamber.