Ten former senior U.S. diplomats and security officials planned to file an affidavit in a federal appeals court arguing that President Donald Trump's executive order curtailing immigration would actually make America less safe.

In a brief scheduled to be filed at 3 a.m. ET on Monday the officials slammed Trump's order as "ill-conceived, poorly implemented and ill-explained."

The brief obtained by NBC News was written jointly by two former heads of the CIA, two former Secretaries of State, a former Secretary of Defense, a former Secretary of Homeland Security, and senior officials of the National Security Council.

More from NBC News:

Appeals Court Rejects Bid to Quickly Restore Trump Travel Ban

Trump, Challenged About Putin, Says 'Our Country's So Innocent?'

Mike Pence: Trump 'Has Every Right to Criticize' Other Branches of Government

"This order cannot be justified on national security or foreign policy grounds. It does not perform its declared task of 'protecting the nation from foreign terrorist entry into the United States.'" the co-authors — Madeleine Albright, John Kerry, Janet Napolitano, Susan Rice, Leon Panetta, John McLaughlin, Avril Haines, Michael Hayden, Lisa Monaco, Michael Morell — wrote in the filing. The list was largely made up of prominent Democrats.

The former officials urged the U.S. 9th Circuit Court of Appeals not to reinstate Trump's entry ban while they decide whether the president has the legal or Constitutional authority to issue the sweeping order.

The affidavit was scheduled to be filed early Monday with the court of appeals in support of Washington state's challenge to Trump's executive order, which temporarily banned entry to the U.S. by people from seven Muslim-majority nations: Iraq, Syria, Sudan, Iran, Somalia, Libya, and Yemen for 90 days. The order banned refugees outside of Syria for 120 days, and Syrian refugees indefinitely.