President Donald Trump said on Monday it is a foregone conclusion that the Democratic-led U.S. House of Representatives will vote to impeach him over his request that Ukraine investigate a political rival as he exhorted his fellow Republicans to rally to his defense.

Trump made his comments at the beginning of a Cabinet meeting at the White House as Democrats sought to build public support for their fast-moving impeachment inquiry even as the administration pressed its efforts to stonewall the probe.

READ MORE: Trump impeachment inquiry puts spotlight on former Texas governor Rick Perry

Story continues below advertisement

Asked if it was a forgone conclusion that House Democrats will vote to impeach him, Trump said yes, otherwise he would win re-election next year. Trump said Republicans need to get tougher and fight the impeachment inquiry, saying Democrats were sticking together.

“They don’t have Mitt Romney,” Trump told reporters.

0:51 Trump will become ‘more erratic’: Biden Trump will become ‘more erratic’: Biden

Acting White House budget director Russell Vought said both he and Michael Duffey, associate director for national security programs at the Office of Management and Budget, would not provide depositions to the committees leading the inquiry in the Democratic-led House of Representatives.

Duffey had been scheduled to testify behind closed doors on Wednesday as Democrats scrutinize Trump’s decision to withhold $391 million in security aid to Ukraine before he asked its president to investigate former Vice President Joe Biden.

Other current and former administration officials have defied White House demands that they not cooperate with the inquiry, which threatens Republican Trump’s presidency. Another round of crucial testimony is set for this week, including by Bill Taylor, the top U.S. diplomat in Ukraine, on Tuesday.

Story continues below advertisement

1:46 Pelosi says House won’t hold vote to authorize impeachment probe Pelosi says House won’t hold vote to authorize impeachment probe

House Democrats released a fact sheet and video to try to make their case for impeachment, drawing on information already made public about the Ukraine scandal. The impeachment inquiry focuses on Trump pressuring a vulnerable foreign ally to interfere to his benefit in the 2020 U.S. presidential election by providing political dirt on Biden, a leading contender for the Democratic nomination to face Trump.

At issue is a June phone call in which Trump asked Ukrainian President Volodymyr Zelenskiy to investigate Biden and his son Hunter Biden, who had been a director of a Ukrainian energy company, as well as a discredited theory that Ukraine, and not Russia, interfered in the 2016 U.S. election. U.S. intelligence agencies and a special counsel have concluded that Russia used a campaign of hacking and propaganda to boost Trump’s candidacy.

READ MORE: Trump impeachment inquiry: Highlights of the testimony so far

The fact sheet and video “encapsulate all the evidence uncovered to date about the president’s months-long pressure campaign to undermine the 2020 election and the extent to which he abused his power by using the levers of government to advance the scheme,” according to House Speaker Nancy Pelosi‘s office.

Story continues below advertisement

Democrats said their fact sheet and video showed that Trump “believes he is above the law” and that “House Republicans’ complicity and silence only serves to keep him there.”

The White House declined to comment.

Trump has lashed out at House Democrats, saying he did nothing wrong and that the Zelenskiy call was “perfect.”

Pivotal Testimony

Diplomat Taylor could be one of the most important witnesses yet. Taylor’s text messages with U.S. Ambassador to the European Union Gordon Sondland have surfaced as a central thread in the probe.

Before making his requests to Zelenskiy, Trump had withheld the congressionally approved U.S. security aid to Ukraine to help Kiev deal with Russia-backed separatists in the eastern part of the country. Zelenskiy agreed to Trump’s requests. Trump later provided the aid.

READ MORE: Trump vs. Pelosi feud ramps up with accusations of ‘meltdowns’ amid impeachment probe

“The President has been crystal clear no quid pro quo’s of any kind,” Sondland responded by text after speaking to Trump. Quid pro quo is a Latin phrase meaning a favor for a favor.

Story continues below advertisement

Sondland said in written testimony last week that Trump in May told senior U.S. officials to deal directly with his personal lawyer, Rudy Giuliani, about U.S. policy on Ukraine, raising concern that American foreign policy was being outsourced to a private citizen and conducted for the president’s personal political benefit.

Also scheduled to testify in a closed session on Wednesday is Philip Reeker, the acting assistant secretary of state for Europe. Laura Cooper, the Deputy Assistant Secretary of Defense for Russia, Ukraine, Eurasia, and Alexander Vindman, a Europe adviser on the National Security Council, are scheduled to testify on Thursday, an official involved in the inquiry said.