A simmering rebellion of conservative populists loyal to President Trump is further endangering the GOP healthcare push, with a chorus of influential voices suspicious of the proposal warning the president to abandon it.

From headlines at Breitbart to chatter on Fox News Channel and right-wing talk radio, as well as among friends who have Trump’s ear, the message has been blunt: The plan being advanced by congressional Republican leaders is deeply flawed - and, at worst, a political trap.

Trump’s allies worry that he is jeopardising his presidency by promoting the bill spearheaded by House Speaker Paul D. Ryan (Wis.), arguing that it would fracture Trump’s coalition of working- and middle-class voters, many of them older and subsisting on federal aid.

Vice President Pence and administration officials scrambled Tuesday to salvage the plan amid widespread dissatisfaction in both the Senate and House over the Congressional Budget Office’s estimate that 24 million fewer people would be insured in a decade under the Ryan proposal, titled the American Health Care Act.

Trump - who has not yet fully used the bully pulpit of the presidency to rally support for the plan - spoke privately with Ryan on Tuesday afternoon. They discussed the various factions, the opinions of several key lawmakers and developing a closing strategy, according to two people with knowledge of the call.

Trump loyalists warned that the president was at risk of violating some of his biggest campaign promises - such as providing broad health coverage for all Americans and preserving Medicaid and other entitlement programmes - in service to an ideological project championed for years by Ryan and other establishment Republicans.

“Trump figures things out pretty quickly, and I think he’s figuring out this situation, how the House Republicans did him a disservice,” said Christopher Ruddy, a longtime Trump friend. “President Trump is a big-picture, pragmatic Republican, and unfortunately the Ryan Republican plan doesn’t capture his worldview.”

Ruddy, the chief executive of Newsmax Media, published a column Tuesday urging Trump to “ditch” the current bill.

Inside the White House, senior officials said they are taking note of the mounting opposition. “You can’t be so blind that you’re not seeing the outside noise,” said one adviser, who spoke on the condition of anonymity because the adviser was not authorised to speak publicly.

A second adviser, who also requested anonymity to speak candidly, said, “We take their views seriously and we’re listening, but we do appreciate when those concerns are shared privately and with a smaller megaphone.”

Keeping Republicans on edge are several Trump advisers with tenuous ties to Ryan and the party establishment who might be more responsive than others to outside pressure, including chief strategist Stephen K. Bannon and senior policy adviser Stephen Miller.

The White House strategy has been to spotlight what it sees as the urgent need to overhaul the health-care system rather than the legislative fix itself. At his Tuesday briefing, press secretary Sean Spicer highlighted “real-life examples” of “actual Americans” who shared with Trump stories of suffering in a listening session Monday.

“These are the stories that are at the top of the president’s mind as he works towards reforming our health-care system,” Spicer said.

This fresh public agitation from Trump loyalists comes as hard-line Republicans in Congress already stand opposed to the health-care bill. These lawmakers, many of whom are members of the House Freedom Caucus, see the proposal as insufficiently conservative because it is too reliant on tax credits and does not fully repeal the Affordable Care Act, the law often known as Obamacare that was signed by President Barack Obama.

Former House speaker Newt Gingrich, a Trump ally, said the president should not be tempted by outside calls to abandon the Ryan bill and should instead “let the legislative process work.”

“What’s happening now is a gut check,” he said. “It’s not unusual. People are figuring out what they’re going to stand tight on.”

The cascade of opposition within Trump’s movement started flowing soon after the bill was unveiled last week and picked up speed this week. On Breitbart - the anti-establishment, conservative news site that has been a platform for Trumpism and was once run by Bannon - article after article has railed against a bill its headline writers excoriate as “RyanCare.”

One heavily promoted story said that RyanCare was “a perverse economic system” and featured an interview with Rep. David Brat (R-Va.), a tea party hero who unseated then-Majority Leader Eric Cantor in 2014.

Breitbart published leaked audio of Ryan on Monday that could undermine his relationship with Trump. The recording is of Ryan on a conference call with House Republicans last year, immediately following the release of the “Access Hollywood” video in which Trump bragged about sexually assaulting women. Ryan said on the call that he was “not going to defend Donald Trump - not now, not in the future.”

Breitbart also has been promoting a rally Wednesday on Capitol Hill organised by FreedomWorks, a right-wing advocacy group that stoked the tea party movement. The event will feature Sens. Ted Cruz (Tex.), Mike Lee (Utah) and Rand Paul (Ky.), who oppose Ryan’s health-care bill.

Paul told reporters Tuesday that the plan was losing momentum: “There’s not really any kind of coalition that’s going to get the Ryan bill to pass. I think the CBO score makes it harder for him to pass his bill, and he’s losing the argument.”

The rush by Ryan to quickly pass the health-care bill concerns some of Trump’s top supporters, including Sen. Tom Cotton (R-Ark.). “I don’t think Americans care whether this bill passes by Easter or Memorial Day,” Cotton said Tuesday on Hugh Hewitt’s radio show.

Republican strategist John Brabender said he observed a number of focus groups of Trump voters in Rust Belt states and found them willing to be patient about the timetable for overhauling health care.

Brabender said the White House “should take a deep breath and not feel like anybody has to rush out and sign something they don’t feel good about... They have to be careful not to just quickly check a box and then own something around their neck for years.”

Cotton dismissed promises from Trump and Republican congressional leaders of an evolving, multiphase process that would continue throughout the year.

“There is no three-phase process,” Cotton said on Hewitt’s show. “There is no three-step plan. That is just political talk. It’s just politicians engaging in spin.”

At the White House, Spicer was confronted at his briefing about Cotton’s criticism as an example of the administration lacking control over what its own supporters are saying. “It’s a free country,” Spicer said. “He can say what he wants.”

Rush Limbaugh echoed Cotton’s concerns on his airwaves Tuesday. The conservative talk-radio commentator said the message from congressional leaders is: “We gotta pass the bill. We gotta send it up to president. No matter what’s in it, we gotta pass the bill.”

“Passing the bill becomes the measure of success,” he continued, “and so that’s when the real dangerous horse-trading begins.”

Limbaugh has sounded protective of Trump, explaining on his show last Friday that the president’s supporters should give him time to work out a better deal because he is “inside the sausage factory” for only the first time.

“Trump is probably finding out just how deeply intertwined the tentacles of this are throughout our society, and what happens when you remove one tentacle?” he asked. “You find six more pop up that you didn’t know were there.”

Fox News host Eric Bolling, who once considered joining the Trump administration and is friendly with the president, published an op-ed Tuesday on the network’s website that said Ryan and the “establishment GOP have pulled a fast one on President Trump.”

“It’s time for President Trump to scrap the GOP health-care bill,” Bolling wrote.

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Conservative talk-radio host Laura Ingraham, a friend of Trump’s who was considered for a job in the White House, said Tuesday on Fox News that the Ryan bill is a “trap.”

“I think Donald Trump is going to get caught on this in 2020,” she said, referring to the next presidential election. “I’d like to spend an hour talking to him about it. I think this is a trap set for Trump, and it’s going to be bad.”

Former senator Judd Gregg (R-N.H.), who was a key player in the battle over the Affordable Care Act in 2010, said of the current situation: “The Republicans are in an impossible position.”

“Most of the people who are in opposition to this have never governed, don’t know how to govern and don’t want to govern,” Gregg said. “Unfortunately, Republicans now control the government and have to learn how to govern. The Laura Ingrahams of the world, who make their money agitating, aren’t functional in a situation where the president has to govern.”