WASHINGTON -- Two more New Jersey Republicans, Reps. Frank LoBiondo and Chris Smith, said Wednesday they would break with their party and vote against the GOP health care bill that would leave 500,000 more Garden State residents without coverage.

LoBiondo (R-2nd Dist.), one of the House Republicans most likely to dissent from their GOP colleagues on votes, and Smith (R-4th Dist.) made their announcements in advance of Thursday's scheduled debate on the American Health Care Act.

"Simply put, this bill does not meet the standards of what was promised; it is not as good as or better than what we currently have," LoBiondo said. "Accordingly, I will vote no on this health care plan."

Smith, who has championed human rights around the world, said he couldn't accept cuts in health coverage for the needy at home.

The Congressional Budget Office said the measure will leave 24 million more Americans without health coverage by 2026 than under current law. In New Jersey, 500,000 residents would lose insurance that otherwise they would have under the Affordable Care Act.

Approval of the legislation remained in doubt just hours before the scheduled vote. Several conservative groups, including the Club for Growth and Heritage Action for America, have urged House Republicans to reject the proposal. Trade groups representing doctors and hospitals also lined up in opposition.

Rep. Leonard Lance (R-7th Dist.), who faced angry crowds at two town hall meetings demanding that he protect their health coverage, said he would oppose the Republican legislation. So will all seven House Democrats from New Jersey.

Rep. Tom MacArthur (R-3rd Dist.) said he was supporting the measure. Rep. Rodney Frelinghuysen (R-11th Dist.), who said the GOP bill was "moving in the right direction to provide quality, affordable health insurance for all Americans," is still reviewing the legislation, spokesman Steve Wilson said.

President Donald Trump, who has embraced the bill despite promising that no one would lose health coverage if the Affordable Care Act was repealed, met with Republican lawmakers at the White House for a second straight day.

He also dropped by a Women in Health Care panel hosted by Seema Verma, administrator of the Centers for Medicare and Medicaid. Participants included Anne Smith Denehy, a West Orange radiologist, according to a list released by the White House.

"Unfortunately, Obamacare is making it much harder for all of the doctors, nurses and health care professionals, men and women alike, to do their job," Trump said, according to pool reports.

The Republican bill would end the Medicaid entitlement program that covers everyone that qualifies for assistance and instead would give a fixed sum to each state, saving $880 billion over 10 years. It would offer tax credits that would be less generous than the subsidies now given to lower-income Americans, and would drop the requirement that everyone buy insurance or pay a penalty.

While reducing coverage for poorer Americans, the bill would repeal all of the health care taxes that fall solely on corporations and wealthy Americans, plus expand two tax breaks primarily used by upper-income taxpayers.

A report issued Wednesday by the Center on Budget and Policy Priorities, a progressive research group said the average Garden State resident buying health insurance off an exchange would pay $2,740 more in higher premiums, co-payments and deductibles under the Republican replacement legislation than under the current health care bill.

MacArthur backed the GOP measure after House Republican leaders agreed to add $85 billion that could be used to help cover insurance premiums of those aged 50 to 64. But the CBPP said that even with the extra money, a 60-year-old in New Jersey with an average income of $22,000 still would pay $8,642 in insurance premiums under the House GOP plan compared with $1,183 under existing law.

Overall, the average New Jersey resident buying health insurance from the exchanges would face additional costs of $2,000 a year, the CBPP said.

The powerful senior citizens' lobby, AARP, called the higher premiums an "age tax" and urged lawmakers to oppose the bill. Americans 50 years of age and older gave 52 percent of their votes to Trump, according to network exit polls.

"This bill, if passed in its current form, will disproportionately hurt older adults between the ages of 50 and 64 by dramatically increasing insurance premiums to unaffordable rates," AARP Executive Vice President Nancy LeaMond said.

Republicans have insisted that the current law is in a death spiral and needs to be replaced as soon as possible.

"The reality is that Obamacare is failing to make health care affordable and is crumbling, with skyrocketing premiums, soaring deductibles, and fewer choices for patients and families," Frelinghuysen said. "We must make positive changes - because doing nothing is not an option."

The CBO and independent health care experts refuted those arguments, saying said the current law is working well for most Americans, that the higher subsidies provided for in the measure have insulated most customers from rising premiums, and a few tweaks rather than wholesale repeal is sufficient to fix any problems.

Republicans said they are prevented in this bill from making other changes to lower costs, such as allowing insurers to sell policies across state lines and limiting how much money patients injured by medical malpractice can collect in damages.

That's because they are using a procedure that will allow the Senate to pass the bill with a simple majority, eliminating the need for Democratic votes. Future health care legislation will need 60 votes and Republicans hold only 52 Senate seats.

Jonathan D. Salant may be reached at jsalant@njadvancemedia.com. Follow him on Twitter @JDSalant or on Facebook. Find NJ.com Politics on Facebook.