NEW YORK (Reuters) - When U.S. Senate Republicans unveil their plan to overhaul America’s healthcare system, they will face a skeptical public that already does not buy the justification for an earlier version that passed the House of Representatives, according to a Reuters/Ipsos poll released on Wednesday.

Protestors gather during a demonstration against the Republican repeal of the Affordable Care Act, outside the U.S. Capitol in Washington, U.S., June 21, 2017. REUTERS/Aaron P. Bernstein

The June 9-13 poll shows that a majority of the country thinks the American Health Care Act would be harmful for low-income Americans, people with pre-existing health conditions and Medicaid recipients.

Overall, 41 percent of American adults oppose the House plan, while 30 percent support it. Another 29 percent said they “don’t know,” according to the poll.

“It’ll make people’s deductibles skyrocket” said Shannon Sowards, 39, of Memphis, Tennessee, a Trump supporter who took the poll. “So I’m not for this healthcare act. I’m for insurance for everyone.”

The Senate is expected to release its full plan on Thursday.

(Click here to view the poll's topline results: tmsnrt.rs/2sqhmM3)

The gap between what Republicans say their plan will do and what people think it will do further complicates matters for Senate Republicans, who already have been criticized for drafting their bill in secret.

“It would be great if a politican had the nerve to be brutally honest” and tell people that healthcare costs are going up, said Joseph Antos, a healthcare expert at the American Enterprise Institute, a conservative think tank. “None of them seem to.”

For years, Republicans have promised voters they would replace Democratic former President Barack Obama’s healthcare law, which they say is too costly and intrusive.

When House Republicans pitched their health plan earlier this year, U.S. House Speaker Paul Ryan boasted that it would lower premiums, protect people with pre-existing conditions and improve public “access” to high-quality, low-cost healthcare. U.S. Representative Tom MacArthur of New Jersey, who helped shape the House bill, said it “would make coverage of pre-existing conditions sacrosanct for all Americans.”

The nonpartisan Congressional Budget Office, however, presented a different view of the bill. It estimated that under the House plan 23 million people would lose their health coverage by 2026 in an effort to cut the federal deficit.

According to the poll, nearly 60 percent of adults said they thought it would make insurance more expensive for low-income Americans and people with pre-existing conditions. Fifty-seven percent said it would make Medicaid less available, and 69 percent said it would cut federal money for Planned Parenthood.

Thirteen percent felt that the House plan would improve the quality of their healthcare, and 9 percent said it would make their healthcare cheaper.

About 28 percent of Americans said they would be “less likely” to support their congressional representative if he or she supported the House plan. Another 16 percent said they would be “more likely” to support their representative and 33 percent said it would make “no difference.”

Republican respondents were more supportive of the House plan than others. And even those Republicans who did not like the House plan said that it is probably an improvement over the current healthcare system.

“It’s not going to change my political views” said Barb Huntington, 64, of Murrells Inlet, South Carolina, a Trump supporter who took the poll.

Huntington, who buys health insurance through her state’s Obamacare exchange, said her premiums went up by $25 per month this year. Huntington said she would not be surprised if they keep going up no matter what the Republicans do.

“It’s going to be like that every year, and we’ll be lucky to have what we have,” she said.

The Reuters/Ipsos poll was conducted online in English across the United States. It gathered responses from 1,492 adults, including 671 Democrats and 501 Republicans. It has a credibility interval, a measure of accuracy, of 3 percentage points for the entire group, 4 percentage points for Democrats and 5 percentage points for Republicans.

(Click here for the survey questions and methodology: tmsnrt.rs/2tty3EI)