WASHINGTON (Reuters) - Congressional Democrats on Friday warned that other associates of President Donald Trump may have lied to Congress, a day after his former personal lawyer, Michael Cohen, pleaded guilty to doing so as part of a probe of Russian meddling in U.S. politics.

U.S. President Donald Trump speaks as he attends the USMCA signing ceremony before the G20 leaders summit in Buenos Aires, Argentina November 30, 2018. REUTERS/Kevin Lamarque

Lawmakers did not level direct accusations at individuals, but the Cohen plea elevated their interest in the veracity of past statements by Trump allies and Trump himself, who was attending the Group of 20 global leaders summit in Argentina.

The Russian meddling probe, led by Special Counsel Robert Mueller, has clouded Trump’s presidency for many months. As the latest developments raised pressure on Trump, he defended his business dealings in Russia when he was running for president.

In early morning Twitter messages from Buenos Aires, Trump said he had “lightly looked” at a real estate project “somewhere in Russia” during his presidential bid, saying it was “very legal & very cool” to do so while campaigning.

Throughout his campaign Trump downplayed his Russian business interests. Cohen pleaded guilty on Thursday to lying to Congress about the timing of efforts to pursue a proposed Trump Organization skyscraper project in Moscow.

Those efforts continued well into the presidential campaign, ending in June 2016, after Trump had clinched the Republican presidential nomination, not in January 2016, before voting in the Republican primaries was underway, as Cohen admitted he had earlier told congressional committees.

At the center of the Mueller investigation, and parallel inquiries by congressional committees, are questions about the extent of Russian hacking in the 2016 election, whether Russia colluded with the Trump campaign and any obstruction of justice.

The Kremlin has denied the findings of U.S. intelligence agencies that it interfered in the 2016 election. Russia and Trump have denied that any collusion between them occurred.

‘WITCH HUNT’

Trump has angrily dismissed the Mueller probe as a “witch hunt” amid concerns in Congress that he might move to fire Mueller, triggering a constitutional crisis.

Legislation to protect Mueller has been proposed, but blocked by Senate Republican leader Mitch McConnell.

While Mueller’s team has charged or secured convictions against more than two dozen Russian nationals and entities, as well as a number of Trump’s associates, House and Senate panels have interviewed more than 50 people.

In the wake of the Cohen plea, Representative Adam Schiff, the top Democrat on the House of Representatives Intelligence Committee, said, “We believe other witnesses were untruthful before our committee.” Schiff is expected to become committee chairman in January when Democrats take control of the House.

Transcripts of hundreds of hours of closed-door congressional interviews have not been made public with the House under control of Trump’s fellow Republicans.

Schiff told reporters he wants all transcripts shared with Mueller. That includes the transcript for longtime Trump ally and adviser Roger Stone, “who similarly may have been tempted to mislead the committee,” Schiff said.

A House Democratic aide, who asked not to be named, said testimony by former U.S. Attorney General Jeff Sessions before the House Judiciary Committee contradicted that of former Trump adviser George Papadopoulos.

Sessions told the committee in 2017 that he resisted a proposal by Papadopoulos to set up a meeting between Trump and Russian President Vladimir Putin. Papadopoulos said in a court filing in September that Sessions supported the idea.

‘LIED TO CONGRESS’

Jerrold Nadler, the top Democrat on the House Judiciary Committee, told reporters on Capitol Hill, “We now know that multiple people lied to Congress and we’ve got to pursue those investigations and get at the truth.”

Democratic lawmakers said they may refer others who have testified on Capitol Hill to Mueller for possible prosecution.

Meanwhile, Mueller’s team told a U.S. judge that new charges may be brought against Trump’s former campaign chairman, Paul Manafort, who is one of numerous Trump associates swept up in the investigation.

Manafort has pleaded guilty to conspiracy against the United States and been convicted separately of bank and tax fraud. He had agreed to cooperate with Mueller, but prosecutors have since accused him of breaching his plea deal by lying to investigators. He has said he disagrees with that accusation.

Manafort, 69, could spend the rest of his life in prison. A federal judge tentatively set a sentencing date for March.

Cohen has been cooperating with Mueller’s investigation since August, when he pleaded guilty to tax and campaign finance violations. He entered a new guilty plea on Thursday, telling the court he misled lawmakers as to the extent of his business dealings with Russia on Trump’s behalf.

“What we learned from Mr. Cohen is two things,” Nadler told reporters on Capitol Hill. “Number one, the president was lying ... when he said he had no business dealings in Russia.”

Nadler added, “The second thing we learned is that during the campaign he was negotiating business deals in Russia ... putting that over his duty to the American people as a candidate for president. The other thing we learned really is Mueller knows a heck of a lot more than is public at this point.”