Reuters sources say that the Trump administration's envoy to Ukraine has resigned, just hours after he was subpoenaed by three congressional committees over the whistleblower furor that's consuming Washington and Kiev.
The exact reason for Kurt Volker's departure isn't yet known, but the House Intelligence Committee, Foreign Affairs Committee, and the House Oversight Committee all demanded depositions from him and four other State Department officials.
His is the first resignation since the whistleblower account emerged.
Volker is specifically named in the whistleblower complaint released on Thursday (September 26).
In it the author -- who Reuters understands was a CIA officer -- says Volker had been attempting to, quote, "contain the damage" caused in Ukraine by President Trump's lawyer, Rudy Giuliani.
Specifically, Giuliani's efforts to press Ukraine into investigating democratic Presidential hopeful Joe Biden and his son Hunter.
It's not clear how his resignation affects the subpoena demand.
Volker had been special representative to Ukraine since 2017, part-time and unpaid.
But he is also a former ambassador to NATO under both Presidents Bush and Obama.
And, he's the director of the McCain Institute, a national security think tank at Arizona State University named for the late Senator John McCain.
Volker was a foreign policy staffer for McCain on Capitol Hill, in the late 90s.