David Holmes blows up one of Trump's key defenses in Ukraine extortion scheme
Olivier Douliery/AFP/David Holmes, a State Department official, arrives Friday afternoon for a closed-door deposition

David Holmes blew up one of the central arguments in the impeachment defense of President Donald Trump.

The president's Republican allies have argued that Ukraine was not aware that congressionally approved aid had been held up by the White House as Trump demanded an investigation of Joe Biden, but Holmes explained why that's wrong, reported the Washington Post.

Holmes, a political counselor at the U.S. Embassy in Ukraine, told congressional investigators that Ukrainian officials seemed to have figured out that the pause, which had been reported in late August by Politico, was related to Trump's call for an investigation.

“(Ukrainian president Volodymyr) Zelensky had received a letter, a congratulatory letter from the president saying he would be pleased to meet him following his inauguration in May,” Holmes said. “We hadn’t to able to get that meeting — and then the security hold came up with no explanation, and I’d be surprised if any of the Ukrainians — you said earlier, we discussed earlier, you know, sophisticated people — when they received no explanation for why that hold was in place, they would have drawn that conclusion.”

The aid was released a couple of weeks later, on Sept. 11, six days after a Washington Post editorial questioned whether the hold was related to Trump's interest in Biden -- and two days after House Democrats announced an investigation of the president and his lawyer Rudy Giuliani's actions toward Ukraine.