Donald Trump had already put a hold on military aide to Ukraine, but email exchanges obtained by The Washington Post show an extensive effort “to generate an after-the-fact justification for the decision and a debate over whether the delay was legal, according to three people familiar with the records.“

The Post has learned of a confidential White House review of Trump’s decision to withhold aid.

The Post writes in August, acting White House chief of staff Mick Mulvaney asked the director of the Office of Management and Budget for an update on the legal rationale for withholding aid. Trump decided in July to not release the millions in assistance to Ukraine without asking if it was legal.

The White House has refused to supply documents to impeachment investigators in Congress.