UPDATE 1-U.S. House panel chairman says Mueller court action imminent

U.S. House of Representatives Judiciary Committee Chairman Jerrold Nadler said he will go to court on Friday to seek access to grand jury evidence compiled by former Special Counsel Robert Mueller's 22-month probe of Russian meddling in the 2016 presidential election. A second pending legal move by Democrats, a federal lawsuit to compel testimony from former White House Counsel Don McGahn about Republican President Donald Trump's efforts to impede the Russia probe, will come early next week, Nadler told CNN.

McGahn, a star witness in the 448-page Mueller report released in April, told federal investigators that Trump directed him to seek Mueller's removal and then to deny that he had been instructed to do so. Democrats view the alleged episode as an act of obstruction of justice that could lead to impeachment proceedings against Trump. "We will win the court fight because the legal excuses the White House has been using are extraordinarily weak from a legal point of view," Nadler told CNN.

Nadler described the pending legal actions, particularly the McGahn lawsuit, as a potential watershed that could dismantle recent White House efforts to stonewall congressional investigators by directing current and former Trump aides to defy subpoenas and refrain from providing testimony. "It will open up the floodgates to all, to enforce all the subpoenas and get all the testimonies because they're all the same nonsense legal argument," he said.

Mueller testified in Congress on Wednesday in back-to-back hearings that Democrats hoped would focus public attention on Trump's alleged misconduct and boost support for an impeachment inquiry. But his halting and reticent performance changed few opinions, leaving House Democrats to accelerate a congressional probe that could take months to bear fruit. House Speaker Nancy Pelosi, who opposes impeachment for now as a politically risky move for Democrats, told reporters that she favored litigation to obtain "the best, strongest possible case" against Trump.

But with the 2020 election campaign season fast approaching, she also made it clear that the impeachment issue would not be allowed to linger. "The decision will be made in a timely fashion. This isn't endless," said Pelosi, who denied suggestions that she was trying to "run out the clock" on impeachment.

Nadler was expected to appear at a noon EDT (1600 GMT) news conference in the U.S. Capitol. Mueller found insufficient evidence to allege that the Trump campaign conspired with Moscow in its effort to help Trump get elected in 2016, although campaign officials met with Russians.

He reached no conclusions on whether Trump tried to obstruct Mueller's inquiry. But Democrats say that testimony from McGahn about Trump's efforts to remove Mueller could give them the evidence they need for an impeachment inquiry. McGahn declined to testify earlier this year after the White House directed him not to cooperate with the committee.