The White House allowed a Trump-appointed official in the Office of Management and Budget to prolong withholding aid to Ukraine after career staff members at the OMB raised a stink about the legality of the move, the Wall Street Journal reported Thursday.

Trump maintains that he ordered the more than $400 million in military aid withheld from Ukraine only temporarily to try to force European countries to contribute more to Ukraine’s defense against Russia. However, in a now-infamous July call with Ukrainian President Volodymyr Zelensky, Trump explicitly asks for a political favor in exchange for the aid. That conversation has formed the basis of the House’s impeachment probe.

According to the WSJ, career officials in the Office of Management and Budget raised concerns after the money was ordered withheld and questioned whether they were legally allowed to not distribute the congressionally-approved funding. After the career staffers raised their concerns with political officials within the office, the White House gave the Associate Director of Nationals Security Programs at the OMB Michael Duffey permission to continue stalling the release of the funds. Duffey is a former Pentagon official and also the former executive director of the Wisconsin Republican Party.

According to a document obtained by the WSJ, the White House also gave Duffey authority to oversee the release of funding from other foreign aid and defense accounts at that same time. The director of the OMB reportedly has the power to delegate oversight of funding approval and release to any staff member within the agency, but the timing and delegation of the work to a political appointee is suspect.

At least five House committees are looking into Trump’s decision to withhold the congressionally approved funding, a sliver of the impeachment inquiry that has raised bipartisan alarm.