The labyrinth of allegations swirling around Donald Trump administration's Ukraine dealings has only deepened since this newspaper's initial coverage of the Mississippi connections, direct and indirect, to the controversy last Thursday. As the scope of the impeachment inquiry grows, key figures have been in and out of closed meetings on Capitol Hill, revealing new information that confirms—and complicates—many of the previous assumptions about the still-anonymous whistleblower's complaint.

This morning, the U.S. Department of State ordered U.S. Ambassador to the European Union Gordon Sondland not to testify before Congress today, setting off another week of acrimony for the emerging impeachment inquiry over President Trump's dealings with Ukraine President Volodymyr Zelensky.

That means that, without a subpoena, the House will not get to question Sondland about his texts with men including Kurt Volker, U.S. special representative for Ukraine. Volker was first under scrutiny in the impeachment inquiry, testifying last Thursday before three U.S. House of Representatives committees: Foreign Affairs, Oversight and Reform, and Intelligence. After this testimony, House Democrats released a transcript of text messages between a number of American and Ukrainian officials, primarily Volker and Sondland, as well as Bill Taylor, U.S. charge d'affaires for Ukraine, top Zelensky aide Andriy Yermak and Trump attorney Rudy Giuliani.

The texts shed light on the deliberate process of dealmaking involved in the Trump-Zelensky relationship, with Volker's texts to Giuliani showing that the former ambassador to NATO connected the former New York City mayor to Yermak, who later met with Giuliani in Madrid. The texts also contain candid discussion of "the deliverable," referring to Zelensky's explicit announcement of an investigation into Hunter Biden's appointment to the board of Burisma Holdings and Joe Biden's involvement in an international effort to dislodge then-Prosecutor General Viktor Shokin. Those texts are:

[8/17/19, 3:06:19 PM] Gordon Sondland: Do we still want Ze to give us an unequivocal draft with 2016 and Boresma?

[8/17/19, 4:34:21 PM] Kurt Volker: That's the clear message so far...

'Security Assistance Is Key'

The key point of contention appears to be a summit between President Trump and President Zelensky, a public mending of the chilled relationship between the U.S. and Ukraine, and communicating that Zelensky had the full backing and support of the current administration. The texts only mention the U.S. continuing to sell Javelin missiles and launchers to Ukraine obliquely, referring to "security assistance," which Bill Taylor brought up in the most incendiary exchange in the release.

[9/9/19, 12:31:06 AM] Bill Taylor: The message to the Ukranians (and Russians) we send with the decision on security assistance is key. With the hold, we have already shaken their faith in us. thus my nightmare scenario. ...

[9/9/19, 12:47:11 AM] Bill Taylor: As I said on the phone, I think it's crazy to withhold security assistance for help with a political campaign.

Hours later, Sondland vehemently denied Taylor's characterization of the deal-making process, insisting that "The President has been crystal clear no quid pro quo's of any kind," despite Sondland's previous messages involving "the deliverable" and the precise crafting of the message intended to announce the investigation of the Bidens.

Not long after the State Department relayed its refusal to allow Sondland to testify, House Democrats announced their intent to subpoena the European Union ambassador, bringing him before the House committees that previously questioned his colleague Kurt Volker. The announcement included additional texts and emails from Sondland's personal device, which Rep. Adam Schiff, D-California, said have been made available to the State Department.

Volker Resigns from McCain Institute

Presently, Kurt Volker is still listed as senior international advisor for the BGR Group, which the Ukraine government hired to represent its interests in Washington, D.C., the month Trump was inaugurated as president. Former Mississippi Gov. Haley Barbour co-founded the lobbying firm that represents many corporations and foreign interests before he returned home to run for governor. BGR spokesman Jeffrey Birnbaum told Politico last week that Volker had recused himself from BGR's Ukraine projects.

The precise nature of Volker's transition to paid lobbyist is unclear, as is the current state of his relationship with the lobbying firm as events unfold. Birnbaum did not return a message by press time.

Volker did, however, continue working as an envoy between Presidents Trump and Zelensky, the texts confirm. It was Volker, who previously was managing director, international for BGR, who first put Andriy Yermak and Rudy Giuliani in contact, as a July 19 text shows:

[7/19/19, 4:48 PM] Kurt Volker: Mr Mayor - really enjoyed breakfast this morning. As discussed, connecting you here with Andrey Yermak, who is very close to President Zelensky. I suggest we schedule a call together on Monday - maybe 10am or 11am Washington time? Kurt

After his testimony before Congress and the release of his texts, Volker resigned from his position as executive director of the McCain Institute for International Leadership, an Arizona-based think tank. Volker cited the media attention resulting from his involvement in the President's Ukraine dealings as a "distraction from the accomplishments and continued growth of the Institute."

Politico reported his potential conflicts of interest working with BGR Group and the McCain Institute because both had financial relationships with Raytheon, which manufactures the Javelin missiles Zelensky is seeking.

Email Nick Judin at [email protected] and follow him on Twitter at @nickjudin. Editor Donna Ladd contributed to this report. Email her at [email protected].