This one’s getting down to the wire. Marie Yovanovitch, the former ambassador to Ukraine, has agreed to meet with three House committees to discuss what she knows about Donald Trump’s actions regarding aid and the push to get the Bidens investigated. Thus far the White House has moved to block any administration officials from testifying at all on anything related to their impeachment push.

Will Yovanovitch show up? Or will Trump invoke executive privilege?

The former U.S. ambassador to Ukraine, Marie Yovanovitch, is expected to appear on Capitol Hill Friday for a closed-door deposition with House committees looking into whether President Donald Trump committed impeachable offenses in asking a foreign country to investigate his political rivals, according to multiple congressional officials with knowledge of the probe.

Yovanovitch’s scheduled appearance comes as the State Department has instructed multiple officials not to testify before Congress and the White House has refused to cooperate with the Democrats’ investigation, calling it a “dangerous” effort to “overturn the results of the 2016 election.”

The State Department could still demand that she not appear, as it did earlier this week with U.S. Ambassador to the European Union Gordon Sondland. That refusal came just hours before Sondland, a Trump mega donor, was to appear.

Yovanovitch should be a person of keen interest to Democrats. She’s a career diplomat at State rather than a political appointee, and indeed still works at State. Trump reassigned her three months before her tour in Ukraine was due to end, thanks at least in part to pressure that may have been generated by Ukrainians running a front PAC here in the US. If anyone has the inside scoop on what Rudy Giuliani and Trump might have been doing in Ukraine, Yovanovitch would.

If she does have that kind of dirt, then one would expect State to instruct her not to testify. And they have some legal cover for that, since Yovanovitch would be discussing sensitive matters under the purview of the executive. That would force the House to seek a subpoena, which State could then fight in court — and ultimately lose, but only after weeks or months of legal wrangling.

Or, rather than fight it in court, the House could move to impeach Trump for obstruction for blocking access to Yovanovitch. Would that fly? Perhaps, but it would be going all-in over a procedural matter rather than actual wrongdoing, which the Senate could dismiss without a second thought. It’s akin to judging a criminal guilty because his attorney offered an objection.

Speaking of subpoenas, there’s more news on the Sondland front, too:

That makes today’s cliffhanger even more instructive. If the White House and State don’t prevent Yovanovitch from testifying, they probably won’t instruct Sondland to defy the subpoena. But if they weren’t going to stop Sondland from testifying, why did they bother to force the House to subpoena him in the first place?

I’d bet on a privilege claim on Yovanovitch, but it will have to come soon.

Update: The first shoe that dropped was Sondland’s, not Yovanovitch’s:

Sondland might be expected to be a little more sympathetic to Trump than Yovanovitch, so this might not produce many fireworks. That may well be why Sondland figures it’s better to get this over with. Via Allahpundit and Axios, that’s apparently what House Republicans believe too.