President bemoans disunity among his party as he faces criticism from a handful of members

Donald Trump on Monday demanded Republicans “get tougher and fight” against an intensifying impeachment inquiry that has strained their allegiance to the president.

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In a meandering, hourlong back-and-forth with reporters a White House cabinet meeting earlier on Monday, Trump said Democrats were “vicious” in their pursuit of uncovering his alleged wrongdoing but that they “stick together”, an insinuation that his party was not as united.

“The Republicans have to get tougher and fight,” Trump said. “We have some that are great fighters, but they have to get tougher and fight, because the Democrats are trying to hurt the Republican party before the election.”

He added: “They don’t have Mitt Romney in their midst. They don’t have people like that. They stick together.”

Trump continues to hold his party captive, and few Republicans have indicated that they are open to efforts to remove him from office. But the chorus of critics, led by Romney, is growing louder as public polling shows a sharp uptick in support for the Democrats’ impeachment inquiry.

Ahead of the meeting, the House speaker, Nancy Pelosi, distributed a “fact sheet” that accused Trump of a “stunning abuse” of presidential power that unfolded in three acts that she headlined the “shakedown”, the “pressure campaign” and the “cover-up”. As Democrats move forward “expeditiously” with their inquiry, the outline may yet serve as a basis for potential articles of impeachment against Trump.

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The president’s exhortation of his party followed a weekend of news reports and interviews that suggested Republicans are wary of defending Trump, particularly in the wake of his decision to abruptly withdraw troops in northern Syria and after he was forced to scrap plans to host the June G7 summit at his Florida resort amid fierce bipartisan backlash.

This weekend, Romney, the 2012 Republican nominee and a persistent critic of Trump, told Axios on HBO it was “shocking” and “a mistake” for Trump to call on Ukraine and China to investigate Joe Biden, the allegation at the heart of the House Democratic-led impeachment inquiry.

In the same episode, Lindsey Graham of South Carolina, one of the president’s closest allies, told Axios he would be open to evidence, outside of Trump’s conversation with the Ukrainian president, that he should be impeached.

Meanwhile, the Florida congressman Francis Rooney became the first House Republican to say that he was willing to consider voting in favor of articles of impeachment against Trump. On Saturday, he announced that he would not seek re-election, perhaps alleviating political pressure over the decision.

The cracks in Republican support for Trump began to appear amid a maelstrom of foreign and domestic chaos of the president’s own making.

Graham along with Romney and the Senate majority leader, Mitch McConnell, have been among the loudest Republican opponents of Trump’s troop withdrawal, which abandoned the Syrian Kurds who fought alongside the US against the Islamic state and cleared the way for Turkey to invade the region. The Turkish offensive has left scores of Syrian Kurdish fighters and civilians dead and displaced hundreds of thousands of residents.

Defense Secretary Mark Esper said on Monday the US may leave a small number of troops in Syria to stop oil fields falling into the hands of Islamic State. Trump has continued to insist that Isis has been defeated, and that only his administration deserves credit for the feat. He has also touted the removal of forces from Syria as a fulfillment of his campaign promise to bring troops home from “endless wars”.

During the meeting, Trump asserted that the US “never agreed to protect the Kurds for the rest of their lives”.

He also dismissed allegations of self-dealing in connection to his canceled plans to host the June G7 summit at his Doral resort in Florida. Referring to the constitutional clause barring gifts from foreign states to federal officeholders, Trump said: “You people with this phony emoluments clause.”

Trump reversed his decision to hold the G7 summit at his Florida resort, reportedly amid pushback from congressional Republicans, which is only the latest sign that cracks are appearing in the president’s base of support among GOP lawmakers.

Meanwhile, Trump’s acting White House chief of staff, Mick Mulvaney, is facing intense scrutiny after acknowledging during a press briefing – and then later adamantly denying – that Trump held up an aid package to Ukraine because the president wanted assurances that the country would investigate Democrats.

“I recognize that I didn’t speak clearly,” Mulvaney said on Fox News Sunday. Asked on Monday whether the president stood by his acting chief of staff, Trump did not respond.

Trump has repeatedly denied that his administration made Ukrainian military aid contingent upon an investigation into a debunked theory about the 2016 election or the dealings of Hunter Biden in Ukraine. In a Monday interview with the Fox News host Sean Hannity, a friend and ally, Trump repeatedly described the conversation with Ukrainian president, Volodymyr Zelenskiy, as “perfect”.

But many, if not most, Republicans have publicly remained loyal to Trump. In the House on Monday, a cohort of far-right conservatives attempted to force a resolution to censure Adam Schiff, the intelligence committee chairman, for “certain misleading conduct” when he dramatized a phone call between Trump and the Ukrainian president. Trump has seized on Schiff’s comments during a hearing last month to suggest the California Democrat committed “treason” and should be impeached. The resolution was blocked by Democrats on Monday evening.

“What the Republicans fear most is the truth,” Pelosi said in a statement after the vote. “The president betrayed the oath of office, our national security and the integrity of our elections, and the GOP has not even tried to deny the facts. Instead, Republicans stage confusion, undermine the constitution and attack the person of whom the president is most afraid.”