President Donald Trump’s former ambassador to the European Union, Gordon Sondland, is suing former secretary of state Mike Pompeo and the U.S. government for $1.8 million to compensate for legal fees incurred during the 2019 House impeachment probe.

The suit, filed Monday in federal court in the District of Columbia, alleges that Pompeo reneged on his promise that the State Department would cover the fees after Sondland delivered bombshell testimony accusing Trump and his aides of pressuring the government of Ukraine to investigate then presidential candidate Joe Biden and his son Hunter in exchange for military aid.

Sondland, a Portland hotel magnate appointed by Trump to serve as ambassador, became a key witness of the impeachment probe because of his firsthand knowledge of conversations with Trump, his attorney Rudy Giuliani and senior Ukrainian officials — as well as his punchy answers, affable demeanor and colorful language.

The allegations in the suit also offer new details on Sondland’s rapid devolution from Trump insider to political outcast in the span of days.

The complaint alleges that Pompeo told Sondland that government lawyers would not be made available to represent him but that if he hired his own counsel, his attorney fees would be covered by the U.S. government. Top aides to Pompeo also acknowledged this commitment, the suit alleges, but “everything changed” after Sondland delivered his testimony alleging a “quid pro quo” and then refused to resign despite a request from one of Pompeo’s most trusted aides, Ulrich Brechbuhl.

“Ambassador Sondland confirmed he would not resign because he did not do anything improper. After that, everything changed. Ambassador Sondland did not receive his attorneys’ fees, notwithstanding the promises from the State Department that the attorneys’ fees would be paid,” the suit alleges.

Sondland is demanding that the U.S. government cover the fees or Pompeo pay out of his own pocket. The suit argues that Pompeo’s actions as secretary of state should not be subject to governmental immunity because the promise “was self-serving, made entirely for personal reasons for his own political survival in the hopes that Ambassador Sondland would not implicate him or others by his testimony.”

In the past year, Sondland’s businesses empire, including several hotels in Portland, was badly hit by the coronavirus pandemic, which decimated tourism across the country. Before being tapped by Trump for the ambassador position, Sondland donated $1 million to the president’s inaugural committee.

Sondland’s falling out with the Trump administration over the legal fees, as described in the suit, coincided with a public falling out during the impeachment hearings.

Initially, Sondland said he had no knowledge of a quid pro quo between the Trump administration and Ukraine. He later revised his testimony and acknowledged that he, in fact, played a role in implementing it.

“Was there a quid pro quo?” Sondland said during his testimony. “With regard to the requested White House call and White House meeting, the answer is yes.”

“Everyone was in the loop,” he said. “It was no secret.”

Trump distanced himself from Sondland following the testimony, telling reporters “I hardly know the gentleman” after praising him as a “great American” just days earlier.

The suit alleges that Sondland’s legal bills were so high in part because the Trump administration restricted “access to materials essential to his preparation,” which forced the legal team to “reconstruct” dates and itineraries and accounts necessary for his testimony.

The State Department paid Sondland $86,040 for his legal fees, which the suit says falls far short of Pompeo’s promise of “full reimbursement.”

Trump fired Sondland on Feb. 7, 2020, two days after the president was acquitted of two impeachments charges in the Senate. Sondland said the firing came “hours” after he refused to resign.

“Since then, the government has bobbed and weaved” in the face of his attorneys’ attempts to recoup the expenses, the suit claims.

A statement provided by Sondland’s attorney, Skip Miller, said the former ambassador “harbors no ill will against” Pompeo but is “simply seeking reimbursement, as was promised by Secretary Pompeo.”

Mark Zaid, a lawyer in Washington who has represented numerous U.S. officials in lawsuits with the government, including the Trump administration, said Sondland’s attempt for reimbursement appears morally justifiable but would be a long shot.

“There should be provisions for government officials who are unwittingly pulled into political battles that they have their legal fees covered,” Zaid said. “He did the right thing. He stepped up and fulfilled his role as a representative of the U.S. government.”

But secretaries of state are often granted broad immunity from actions they take while in government, he said. “The sad fact is that sometimes doing the right thing doesn’t lead to a reward, and unfortunately it has a cost,” he said.

Ashley Parker contributed to this report.