Three-fourths of the U.S. Citizenship and Immigration Services workforce — more than 13,000 employees — could be told as soon as Wednesday that they face extended furloughs starting Aug. 3 that would cut off their salaries and severely curtail the agency’s work, the union representing the employees has said.

The agency has said it will need to take that action unless it receives a cash infusion from Congress because the fees from visa and citizenship applications and other services it provides are down sharply in the wake of the novel coronavirus pandemic. Those fees largely fund the operations of USCIS, which is a component of the Department of Homeland Security.

Officials with the American Federation of Government Employees said that USCIS management told them Tuesday that notices of potential furloughs will be sent between Wednesday and July 3, under government personnel rules requiring advance notice when a furlough is projected to last 30 days or more.

“We got the distinct impression that they didn’t want to do the furloughs but if they didn’t get money from Congress they’re going to have to,” said Danielle Spooner, president of AFGE Council 119. Many of the potentially affected employees are immigration services officers who make determinations on applications for various types of immigration benefits, she said.

While layoffs aren’t being threatened, “There’s still a lot of questions and uncertainty,” added Kenneth Palinkas, executive vice president of the council. Both he and Spooner are USCIS employees but stressed that they were speaking in their union capacities and on their own time.

The notices would come close on the heels of an executive order from President Trump barring many categories of foreign workers and curbing immigration visas through the end of the year — actions that in turn would further erode the agency’s main source of funding.

“Due to the COVID-19 pandemic, USCIS has seen a dramatic decrease in revenue and is seeking a one-time emergency request for funding to ensure we can carry out our mission of administering our nation’s lawful immigration system, safeguarding its integrity, and protecting the American people,” a USCIS representative said in an email. “Without congressional intervention, USCIS will need to administratively furlough approximately 13,400 employees.”

Concern about potential furloughs at the agency has been building since mid-May when the agency told Capitol Hill that income from fees — which fund about 97 percent of USCIS operations — had fallen by half during March and April and were projected to be down by 60 percent through the remainder of the government’s fiscal year, which ends Sept. 30.

The agency said it needed an additional $1.2 billion to be spread over the rest of this fiscal year and the start of the new one, while recommending a 10 percent surcharge on application fees to cover the cost. The agency at the time anticipated that a furlough might begin July 20 but was able to extend the date to August 3 through cost-saving steps.

“With a loss of nearly three-fourths of its workforce, work, student and visitor visa petitions, asylum and citizenship/naturalization applications, green cards, and refugee applications will not be processed,” AFGE National President Everett B. Kelley told a House hearing last week.

“We recognize the enormous economic pain that the COVID-19 pandemic has caused throughout our nation and the world. But the United States should not and need not discontinue its capacity for administering legal immigration processes. But without this supplemental appropriation, that is exactly what will happen,” he said.

The White House’s Office of Management and Budget said in a letter to Congress several days later that “USCIS will not have sufficient funding to maintain operations through the end of the fiscal year, nor will USCIS have balances to fund its operations during the first quarter of fiscal year 2021.”

The OMB letter, though, does not include the details required of a formal request for a budget supplement, which “makes it more difficult for Congress to take action to address the shortfall at USCIS,” House Appropriations Committee Communications Director Evan Hollander said in an email.

“However, House Democrats are closely tracking USCIS’ financial difficulties, and are prepared to discuss solutions with Senate Republicans as part of negotiations on the next phase of coronavirus response legislation,” he said.

The threatened furloughs at USCIS would be the most extensive in the federal workforce since mid-2013, when numerous agencies put some employees in unpaid status for several days scattered over the summer because of “sequestration” budget limits.

In that type of furlough, what the government calls an “administrative” furlough, employees are not later paid. That is in contrast to “shutdown” furloughs caused by lapses in funding, which have occurred several times in recent years and in which affected employees later are paid as though they had worked.

Although several other federal agencies, or portions of them, operate at least in part on fees they charge, the USCIS is the first to move toward furloughing employees to cover the costs of reduced income resulting from the pandemic.

At last week’s hearing similar concerns were raised regarding Customs and Border Protection — also a component of the Department of Homeland Security — but that agency afterward said that there is no imminent threat of furloughs.