WASHINGTON — An ambassador who’s emerged at the center of President Trump’s Ukraine scandal will testify to Congress next week, defying State Department orders, his attorneys said Friday.

Gordon Sondland, the U.S. ambassador to the European Union, will appear before the three committees leading the House impeachment investigation next Thursday.

“Notwithstanding the State Department’s current direction to not testify, Ambassador Sondland will honor the Committees’ subpoena, and he looks forward to testifying on Thursday,” Sondland lawyers Robert Luskin and Kwame Manley said in a statement.

Sondland made a number of trips to Ukraine over the summer, and the fact that the country is not part of the EU has raised questions as to why he was there in the first place. Text messages between him, Acting U.S. Ambassador to Ukraine Bill Taylor, and then-U.S. Special Envoy to Ukraine Kurt Volker suggest that Sondland was a key player in working to push Ukraine to investigate former Vice President Joe Biden at President Trump’s behest.

Sondland was also mentioned by the anonymous intelligence-community whistleblower whose complaint launched this investigation — they said Sondland helped “‘navigate’ the demands that the president had made of" Ukrainian President Volodymyr Zelensky.

Sondland had been scheduled to testify earlier this week but was blocked by the State Department. Later that day, the White House announced it wouldn’t cooperate in any form with the House’s impeachment investigation, and planned to stonewall all requests.

It’s unclear how substantive the testimony will be or how open Sondland will be with the committees. Sondland’s attorneys say he won’t be able to produce the documents and materials relevant to the case that the committees have requested, arguing that federal law and State Department regulations bar him from sharing those materials without approval from the Secretary of State, though they request that his bosses agree to share the relevant information before his Thursday testimony.