President Trump’s signature policy for veterans — allowing more of them to shift their health care from the government-run system to private doctors and hospitals — is under attack from newly empowered Democrats and their allies on Capitol Hill.

Veterans Affairs Secretary Robert Wilkie is moving quickly to roll out new rules by June that would expand access to private care, especially for veterans in rural and congested areas, if they have a 30-minute drive to receive primary care.

Within two years, as many as half the 7 million veterans now seen at VA could receive their care elsewhere, advocates of the change say.

Trump’s proposed budget, released last week, includes up to $3.2 billion in new spending next year for private-sector visits, including to walk-in clinics.

VA, with 1,200 hospitals and clinics, is the country’s largest health-care system. For conservatives who failed to repeal the Affordable Care Act, rerouting veterans’ care to the private sector is the next front in the battle over U.S. health policy. For President Trump, giving veterans more choices will probably be a reelection theme next year as he seeks shorter waits and potentially better care for veterans, a crucial constituency.

Democrats now in charge in the House are resisting. They say proposed rules on when veterans could go outside VA are too lenient and would damage the government system — a long-held fear of Democrats who worry that union jobs will be siphoned off and the government system dismantled.

While not directly opposing a veteran’s right to see a private doctor, opponents are undermining the new policy in hearings, statements and letters and preparing for aggressive oversight as VA rolls out rules to put in place legislation Congress passed last year.

Democrats and some veterans groups have accused Wilkie of leaving them out of planning. “They profess to be against privatization,” said Rep. Mark Takano (D-Calif.), who ascended to chairman of the House Veterans’ Affairs Committee in January, “but by default, we will see privatization happen under our very noses.” House Speaker Nancy Pelosi (D-Calif.) has raised alarms for months that the policy lacks a “sustainable funding source.”

VA Mission Act’s bipartisan passage was a victory for the president, who vowed to revamp veterans’ access to a health-care system beset by poor access after a 2014 scandal.

The law boosted a group backed by billionaire industrialist Charles Koch that has shaped Trump’s veterans policy. Concerned Veterans for America has quickly mobilized against the law’s critics, launching a paid lobbying campaign this month to defend it.

Meanwhile, the American Federation of Government Employees — the largest federal employee union — is mobilizing its 230,000 VA members to pressure Wilkie to fill some 42,700 health-care vacancies, criticizing him for giving short-shrift to hiring.

VA officials note that the law passed Congress with overwhelming support — and authorizes the secretary to set the rules. They dismiss Democrats’ privatization claims and say they do not envision a massive exodus to the private sector beyond the 34 percent of appointments now there.

“VA has more employees than ever before, its budget is bigger than ever before and the department is completing more internal medical appointments than ever before,” spokesman Curt Cashour said in a email.

But Wilkie has told VA employees and lawmakers the Mission Act will “fundamentally transform VA health care,” calling it the biggest change since World War II. A senior VA official and an advocate with knowledge of the planning process estimate a dramatic increase in the use of private doctors.

The confrontation has been building since Trump took office. Trump’s first VA secretary said he was forced out by privatization zealots and said private care would result in exorbitant costs to taxpayers.

Many Democrats supported the Mission Act, which included an expansion of a popular stipend for caregivers. But they are signaling a fight now in part because of a decision by Congress to eliminate a separate source of funding for private care that Congress authorized when it first nudged veterans to the private sector in 2014.

That has raised fears that money will bleed from VA’s health-care budget.

Under current rules, veterans can choose to see an outside doctor if they would have to wait 30 days for an appointment with a VA provider or travel at least 40 miles.

The new rules would loosen the standard to a 20-day wait or a 30-minute drive for primary care, and an hour for specialty care. The 20-day standard would decline to 14 days next year.

Veterans will also have access to private walk-in clinics that will contract with VA, with the first two visits free and the third requiring a $30 co-pay.

In general, veterans receive free care for service-related injuries and ailments and are charged low co-pays for other care.

The private option appealed to some veterans leaving the District’s busy VA hospital one afternoon last week.

Luis Becorena, 35, who served in the Marines in Iraq, was waiting for a bus after visiting the walk-in clinic for stomach pain. He has private insurance through his job as an immigration officer at the Department of Homeland Security.

But he does not like the co-pays. He said he has waited as long as a month to get in to see his primary care doctor at VA and once spent four hours in the emergency room waiting to receive treatment.

He said he is looking forward to being able to go to a private walk-in clinic near his home in Silver Spring — and have VA pay. “It can be crowded here, and I need a backup.”

John Bray, 71, a retired banker from Bethesda who served in Vietnam, had just attended an information session for a colonoscopy.

He has private insurance through Medicare Advantage but chooses VA, he said, because of the high quality of its doctors.

“If you’re in the middle of nowhere, you should be able to go to your local doc,” he said, “but I don’t think you have to take [most] people outside to the private system. I don’t know that it will lower costs.”

VA says it does not know how many more veterans will choose to leave the system.

About 80 percent of veterans enrolled in VA also have private insurance, and some experts and former agency officials predict that once the government pays for them to see private doctors without co-pays or deductibles, they will flood the private system. That could be expensive.

Congressional aides briefed by VA in recent months received estimates of $19 billion to $22 billion over five years.

But previous studies, including by the Congressional Budget Office, have estimated far higher costs, depending on where the bar for access to private care is set.

VA budget officials said last week that if their estimates prove to be wrong, they will ask Congress for permission to shift money from other programs into the fund reserved for private-sector care.

The political armies are motivated. Concerned Veterans for America this month launched a digital advertising, lobbying and grass roots campaign to promote “choice,” investing more than $100,000 to defend the law and preserve its intent.

A new website,, aims to dispel what the group says are myths about private care. The group says it could also target lawmakers who push back against the changes.

“We will be very active,” said Dan Caldwell, Concerned Veterans’ executive director. The new standards “shouldn’t surprise anyone, given that the president has advocated for more choice for veterans. If members of Congress were uncomfortable with the law, they shouldn’t have voted for it.”

The union is pressing VA to fill vacancies. The agency says its health-care budget has expanded to meet the needs of aging Vietnam-era veterans and those returning from the wars in Iraq and Afghanistan.

Some vacancies are normal, they say, given normal rates of turnover and retirement.

“They should not expand private care until they achieve full staffing internally,” said Marilyn Park, a legislative representative for the union, a generous donor to congressional Democrats.

Correction: An earlier version of this story incorrectly said the White House eliminated a separate source of funding for private care. That decision was made by Congress.