Washington • President Donald Trump, increasingly embittered by an impeachment inquiry that Democrats are intensifying by the day, complained on Monday that Republicans were not united enough in defending him against what he called “vicious” adversaries bent on removing him.

Trump lashed out at Sen. Mitt Romney, R-Utah, the only member of his party who has signaled he may be open to impeaching Trump, arguing that the senator’s defection showed weakness in the party.

Launching into a series of attacks on Democrats, Trump said approvingly that they were “vicious and they stick together. They don’t have Mitt Romney in their midst — they don’t have people like that.”

“They stick together,” Trump added, during a lengthy question-and-answer session with reporters at a Cabinet meeting. “You never see them break off.”

It was the second time in as many days that Trump — coming to terms with the fact that he will most likely be impeached by the Democrat-led House within weeks and face a Senate trial immediately after — has complained about a lack of support from Republicans as he faces the greatest threat yet to his presidency.

“When do the Do Nothing Democrats pay a price for what they are doing to our Country, & when do the Republicans finally fight back?” Trump tweeted late Sunday night.

The president’s angry response comes as Democrats, determined to sustain public attention and support for the impeachment inquiry, keep up a daily drumbeat of depositions, subpoenas and new revelations. They are pressing to keep momentum for the investigation with meticulous planning, frequent talking points for lawmakers and a steady menu of incremental developments to feed to a press corps hungry to cover a historic proceeding.

At the same time, cracks have emerged in the normally unapologetic monolith of Republican support for Trump on Capitol Hill as the impeachment inquiry marches on. Some Republicans, already uneasy about the allegations at the heart of the Ukraine inquiry, have grown increasingly uncomfortable with Trump’s behavior, and unwilling to defend him on a range of topics, including his decision to pull back U.S. troops from Syria and his plan — abruptly abandoned in the face of a bipartisan outcry — to hold the Group of 7 summit of world leaders at one of his resorts in Florida.

The admission — later recanted — by Mick Mulvaney, the acting White House chief of staff, of a quid pro quo linking foreign aid to Trump’s effort to pressure Ukraine to investigate his political rivals, was a worrying piece of evidence for nervous Republicans that the president and his team are woefully unprepared to confront the impeachment onslaught.

Romney, a frequent Trump critic, has called the president’s attempts to solicit dirt on a political rival “wrong and appalling,” making him one of the most outspoken Republicans on the president’s behavior in office, and has declined to rule out impeaching him. In a fiery speech last week, Romney, the 2012 Republican presidential nominee, said the Syria withdrawal would be seen as “a bloodstain on the annals of American history.”

While there is no evidence that other Republicans are taking their cues from Romney, he is not the only member of the party to publicly express concern. Sen. Lisa Murkowski, R-Alaska, said last week that a president should never “hold up foreign aid that we had previously appropriated for a political initiative. Period.” Rep. Francis Rooney, R-Fla., who announced that he will not run for reelection, refused to rule out supporting impeachment. John Kasich, the former Republican governor of Ohio, said impeachment should move forward.

During remarks at the White House, the president blasted House Democrats for pursuing impeachment, calling the effort to oust him “very bad for our country” and suggesting that dealing with the inquiry was getting in the way of more important presidential actions.

“In the midst of that, I’m trying to get our country out of wars,” Trump said. “I have to fight off these lowlifes at the same time I’m negotiating these very important things.”

But his anger at his own party was also clearly on display, as he chastised a group of lawmakers, operatives and former officials who sought to prevent Trump from becoming the Republican presidential nominee in 2016 and vowed that they would never work for or support him, often referred to as “Never Trumpers.”

“Those people may be worse than the Democrats, the Never Trumpers,” he said.