The Biden administration is selling its new order that 2.1 million civilian federal employees get vaccinated or face repeated testing as a bold step that will allow the government to safely bring its workforce back to the office and resume normal operations, even as the highly contagious delta variant surges.

But for many federal agencies, the White House’s public stance and its internal communications with civil service unions — committing to a return to the office for hundreds of thousands of employees and contractors still logging in to work from the safety of their homes — belies the reality on the ground.

Carefully developed plans to begin phasing staffs back after Labor Day are now in jeopardy, officials say privately, with the Pentagon sending thousands of employees home on Monday — just three weeks after recalling more people to the building. Meanwhile, leaders at the Department of Veterans Affairs are in daily discussions about whether to tell their teleworking staffs they should not return after the holiday after all, officials said.For the moment, “VA remains in a maximum telework status keeping employee safety at the forefront,” press secretary Terrence Hayes said in an email.

Federal managers say they have little idea how to roll out a massive, first-of-its-kind plan to ask employees whether they’re vaccinated, impose testing as frequently as twice a week if the answer is no and move to dismiss them if they’re found to be untruthful. And many workers in the country’s conservative pockets who mistrust the vaccine and oppose anyone in government who forces them to get it say they will continue to resist.

“At this point, we don’t know anything about how the vaccine policy will be implemented,” said Ann Stefanek, a spokeswoman for the Air Force, which employs about 200,000 civilians. “There’s still not a mechanism right now to collect this information on whether you’re vaccinated or not. Are we talking about entering this on an Excel spreadsheet?”

An official with the Office of Management and Budget said guidance on how the vaccine plan should roll out will be coming to federal agencies “in the near future.”

The new virus surge is already affecting crucial federal operations. VA’slaw enforcement training center in Little Rock has shut down indefinitely following a coronavirus outbreak in July among unvaccinated students, the agency said, with 39 students and instructors falling sick, two of them hospitalized.The same month, the virus tore through U.S. Forest Service crews battling a wildfire in Oregon. And a review of another cluster of cases among firefighters in California in June found mixed vaccination status and little mask-wearing, according to the National Federation of Federal Employees, their union.

Meanwhile, some agencies face mounting pressure from lawmakers to reopen offices. The Social Security Administration came under criticism from the agency’s inspector general last week for allowing thousands of sensitive documents from claimants seeking a variety of benefits to go unprocessed for as long as a year, as 1,500 field offices remain closed to the public.

Social Security spokeswoman Nicole Tiggemann said acting commissioner Kilolo Kijakazi has directed a review of mail processes to make changes. She declined to say when field offices plan to reopen, referring inquiries to the White House budget office, which must approve the plan.

An employee at a Social Security field office in Fayetteville, N.C., who spoke on the condition of anonymity because they were not authorized to speak to the press, said the agency had been talking about reopening since March, but nothing was firm. At times, about a quarter of the staff of 50 has come in to meet with claimants. But the work — which in normal times involved interacting with about 300 members of the public coming in to a small indoor space on an average day — has been complicated by the pandemic and the latest surge in cases, regardless of how many workers got vaccinated.

“I hope to be able to stay at home,” the employee said. “With our office, you’re always around a lot of people.”

The delta variant is also upending plans to return federal staffs to field work they have had to perform remotely — and in some cases less effectively — during the pandemic. The VA’s inspector general’s office was scheduled to resume in-person inspections of health-care facilities in September, but those plans are on hold, officials said.

The uncertainty at federal agencies unfolds against a tense backdrop. The country’s reopening is paused, with caseloads surging dramatically through the South and rising in nearly every state, an increase public health experts say is driven largely by the high number of unvaccinated people in the United States.

As the country’s largest employer, the federal government’s decision to reopen — or not — sends an important signal. Any sign the government is hesitating to bring non-front-line staff back to the office suggests the country will not be returning to anything close to the rhythms of the pre-pandemic workday any time soon.

In the private sector, office reopenings for employees who have worked remotely throughout the pandemic began to pick up speed earlier this summer, but the trend is in danger of reversing. A slew of companies have delayed planned fall returns in recent days, among them the New York Times, The Washington Post, Apple and Twitter.

The new policy President Joe Biden announced last week requires civilian federal employees and contractors to attest to their vaccine status or face regular testing, mandatory mask-wearing and restrictions on work travel. But the unvaccinated will be able to work with their vaccinated colleagues, provided they continue to test negative.

Defense Secretary Lloyd Austin said during a trip to the Philippines last week that he is inclined to seek authorization to make the vaccine mandatory for active-duty troops.

The government has never stood up an effort on this scale so quickly, officials said, with competing pressures to keep employees safe, restart services to the public and not alienate those who refuse the vaccine. Just 15 percent of the federal workforce lives in the Washington area, raising questions about how vast swaths of unvaccinated employees in red states will approach Biden’s directive.

“People who have had the ability to telework are really insisting on the vaccine, but in our body, you’re seeing a split,” said George “Joe” Pauley, second vice president of the American Federation of Government Employees Northeast Local 137, which represents Agriculture Department food inspectors,referring to the vaccine-skeptical mind-set of many front-line workers. Pauley, who lives in Upstate New York, declined to say whether he is vaccinated and does not plan on telling his bosses when asked, he said. It is nearly impossible to separate inspectors and employees by six feet in processing plants, so by asking their vaccine status, “what have you gained?” he said.

His case presents just one of many challenges the new vaccine requirement is creating. Managers and their staffs wonder what disciplinary action will confront unvaccinated employees who refuse to get regular coronavirus tests or are discovered to have been dishonest about their vaccine status - and how much leeway agencies will have in disciplining them.

Although the new safety protocols apply to employees and contractors “while in the workplace,” teleworking employees will have to attest to their status but will not need to be tested if they don’t come into the office, according to details the National Treasury Employees Union said it received from the White House in recent days.

Agencies will be expected to pay for testing — and devise systems to store and easily retrieve a new form of medical information.

A further complication could come from the unions, some of which have hesitated to comment publicly on the vaccine directive because it has split their membership. AFGE, the largest with 750,000 members, has demanded bargaining over the implementation of the policy, potentially delaying the rollout. Other unions are expected to follow suit. Agencies are legally required to bargain before carrying out any new workplace policy, although this one may qualify as an emergency that could take effect before labor and management reach an agreement, officials said.

The White House budget office said employees can choose not to provide information on their vaccination status, in which case they will be treated as unvaccinated. The administration stressed that although the system will be self-certifying, anyone found to have been dishonest can be fired, because providing false information to the government is a federal crime.

As uncertainty pervades back-to-the-office planning that seemed certain only weeks ago, federal agencies have communicated little with the public or with their staffs about their plans. VA Secretary Denis McDonough told the skeleton crew working at the agency’s Washington headquarters to return to working from home if possible. The International Trade Administration at the Commerce Department has not notified its teleworking staff of a return date, and neither has the Department of Housing and Urban Development. The Federal Trade Commission, which had planned a September return, is now back to “maximum flexibility,” an employee said.

As they begin to implement the new vaccine directive, agencies are “. . . evaluating any potential operational impacts on reentry timelines and approaches,” the White House budget office said in an email.

Most agencies do not know how much of their workforce has been vaccinated, since until now they have not asked. But union and management officials guess the numbers reflect national trends, which show about 61 percent of adults over 18 are fully vaccinated. The numbers are lower in conservative areas of the country - and that’s where the new policy is stirring anger and confusion.

A Federal Bureau of Prisons employee at FCI Herlong, a medium-security federal prison in California, said he and many of his colleagues are unvaccinated and plan to stay that way.

The employee, who spoke on the condition of anonymity because he was not authorized to speak publicly, questioned how officials would implement the stringent testing protocol at places like prisons, noting that the issue of signing in — and what type of tasks workers could be on the clock for — had been a subject of tension and litigation at the prison for years. During an outbreak at the facility last fall, long lines were common at the voluntary testing station at the prison, and some employees were using the waits as a way to milk the clock, he said.

“We’re already so short, and so many prisons are, that they can’t really demand anything,” he said. Current mask requirements and temperature checks have fallen by the wayside, he said. “If they sat me down in a chair and said we’re going to poke you or you’re going to have to retire, I’d retire.”

Will Kohler, a tax examiner with the Internal Revenue Service in Cincinnati and a guild steward with the National Treasury Employees Union who has been working remotely since the pandemic started, said the reopening date at his facility had been pushed back about 10 times. Employees recently received an email from management telling them that no return was planned for now because of the delta variant.

“Now it’s open-ended,” Kohler said. “Until further notice ... it’s like we’re hanging on the hook.”

His office is open for those with tasks that cannot be performed remotely, like people who work with paper files, and those who choose to come in voluntarily. But few are doing so, he said.

The National Science Foundation also has not set a firm return date, said an employee who spoke on the condition of anonymity for fear of reprisal. He said he had been vaguely told by a supervisor in June that the return would be in September but assumed that informal date had changed, though there have been no agencywide communications about the issue.

The employee, who is in his 20s, said he was hoping to get back into the office and is frustrated with lagging vaccination rates in the country.

“Since I took personal responsibility to protect myself and those around me, I don’t think it’s fair that I should have to suffer consequences from the selfish decisions of those who choose not to get the vaccine,” he said.