The U.S. ambassador to the European Union, Gordon Sondland, was scheduled to testify before a closed-door meeting of the House Intelligence Committee Tuesday morning. However, the State Department blocked him from appearing before the committee, despite Sondland having traveled from across the Atlantic for the deposition.

Committee chairman Adam Schiff told reporters that he received only an hour-and-a-half notice from State Department lawyers that the ambassador would not appear. He called the failure to produce the witness, and additional documents, “yet additional strong evidence of obstruction of the constitution.”

Speaking briefly after the chairman, Rep. Jim Jordan, who serves as ranking member of the Oversight and Government Reform Committee, told the gathered press, that he can “understand the reason why the State Department decided not to have [the ambassador] appear” Tuesday. The Ohio congressman cited “the process” and Schiff’s treatment of former U.S. envoy to Ukraine Kurt Volker during a deposition last week.

[Read more: Impeachment news roundup for Oct. 8]