Facing a felony count of lying to the Justice Department, former Obama White House counsel Gregory B. Craig on Wednesday testified that his legal work for the Ukrainian government never “crossed the line” into advocacy and that he never misled U.S. officials about whether his contacts with journalists required him to register as a foreign agent.

“I did not lie,” Craig told a federal jury in Washington. “I did not withhold or conceal any information.”

Craig’s day-long testimony in his own defense marked the dramatic climax of his three-week trial over whether he made false statements to officials investigating whether he and his law firm, Skadden, Arps, Slate, Meagher & Flom, should have registered as foreign lobbyists for legal and public relations work he did with GOP power broker Paul Manafort on behalf of the Ukrainian Justice Ministry in 2012.

Craig, 74, has pleaded not guilty to the charge, which carries up to a five-year prison sentence, although federal guidelines for a first offender include probation.

Spun off from special counsel Robert S. Mueller III’s Russia probe, Craig’s prosecution has riveted Washington’s political class, threatening the reputation of one of the capital’s most respected Democratic attorneys, while extending the Mueller investigation’s crackdown on the secret and at times grubby machinations of a small brigade of American lawyers, lobbyists and publicists employed by foreign governments to influence U.S. politics.

Manafort helped arrange for Craig and Skadden to be hired to write a report reviewing the jailing of Yulia Tymoshenko, a political rival of Ukrainian President Viktor Yanukovych, whom Manafort served as a political adviser.

The report offered a mixed review of her trial. But Ukraine’s government made the report the centerpiece of an undisclosed lobbying campaign to improve Yanukovych’s reputation in the West.

Prosecutors allege Craig did not want to register because he believed it could impede Skadden team members from entering government service and because he feared having to disclose that Ukrainian businessman Viktor Pinchuk had paid the firm $4.15 million for the report, undermining perceptions of Skadden’s independence.

The government said Craig’s outreach to journalists to explain and publicize the report in December 2012 triggered a requirement to register under the Foreign Agents Registration Act, and that he deliberately lied about the timing and scope of his actions and his part in an orchestrated campaign to influence U.S. opinion for a foreign politician.

Craig testified Wednesday that his speaking with reporters may have been part of a broader public-relations campaign but that that was not his reason for reaching out.

Instead, Craig said, he spoke with reporters to refute mischaracterizations spread by Ukraine’s representatives about the work, media spin that he said he opposed because it created the impression the law firm was “bought and paid for” to whitewash Ukraine’s prosecution of Tymoshenko.

“I was not acting in the interests of the Ukraine. I was defending the integrity of the report,” Craig said, under questioning from defense attorney William Taylor. “I did not think any of those contacts made me a press agent or agent for Ukraine . . . If we’re taking actions contrary to the interests of our client, how can you say we’re acting as agents of the client?”

Prosecutors allege Craig in an Oct. 11, 2013, letter to the Justice Department’s FARA enforcement unit falsely said Skadden did not advise Ukraine about the distribution of the report, and that he gave a copy to the New York Times only at its request.

Rather, they allege, he wrote national security correspondent David E. Sanger to solicit coverage and hand-delivered a report copy before its public release to Sanger’s home, with Craig allegedly saying Ukraine had determined the reporter should get a “first look at it.”

Craig testified he agreed to handle communications with Sanger only after Sanger was contacted by Jonathan Hawker, a publicist then working for FTI Consulting, which was part of a lobbying operation run by Manafort and his deputy, Rick Gates.

Gates had testified earlier in Craig’s trial that, to his knowledge, it was Craig who first brought up the possibility of “seeding” news coverage in the Times with Sanger.

In his testimony, Craig denied proposing that option and said he spoke with Sanger only because he said he had“no confidence” in Hawker’s honesty.

“I was concerned he would be more concerned with pleasing Mr. Gates and Mr. Manafort than being faithful with the findings of our report,” Craig said, adding of Hawker, “I wasn’t part of his team. He wasn’t part of my team.”

Prosecutors led by Assistant U.S. Attorney Fernando Campoamor-Sanchez in cross-examination — to be continued Thursday — elicited that Craig had recommended the hiring of FTI, and met with Manafort, Hawker and others at the Harvard Club of New York on Sept. 23, 2012, to discuss the media rollout.

“Well done,” began an email by Manafort to Craig after news articles appeared, Craig also acknowledged on the stand. “The pro has emerged again. The initial roll out had been very effective and your backgrounding has been key to it all,” Manafort wrote in the email referred to in court.

Manafort is serving a 7½ -year prison sentence for conspiracy and financial fraud crimes in Mueller’s probe, including for hiding more than $30 million he was paid for his undisclosed Ukraine lobbying work.

Campoamor-Sanchez questioned whether Craig was motivated by the sums Ukraine was ready to pay, noting that his Skadden teammate at the time, Clifford Sloan, at one point had written him, “Don’t be bashful about asking for a lot.” Earlier testimony showed Manafort and Craig agreed to backdate a $1.25 million Skadden invoice that understated how much Ukraine had already paid the firm through Pinchuk’s initially secret transactions through an offshore account.

Craig said bringing in business for Skadden was one motivation, along with the legal and foreign policy challenges of the project, and the chance “to make a difference” by helping Ukraine resolve deep internal political divisions. Craig joined Skadden after leaving the Obama White House in 2010 and retired from the firm last year.

The white-haired Craig appeared relaxed and lighthearted as he testified in a crowded courtroom that included his family members and friend Harold M. Ickes, a longtime ally of the Clintons and former White House deputy chief of staff. Jessie K. Liu, U.S. attorney for the District of Columbia, also attended parts of Craig’s examination.

Ann E. Marimow and Lynh Bui contributed to this report.