It might have just gotten a lot harder for undocumented immigrants to stay in the U.S., because—according to immigration attorneys—some Immigration and Customs Enforcement field offices have taken away a key legal strategy that let undocumented immigrants ask prosecutors to temporarily postpone their deportations.

Immigration attorneys told The Daily Beast that the ICE field office in Buffalo, N.Y., as of Friday afternoon, has stopped granting any requests for prosecutorial discretion. This means immigrants who haven’t committed crimes and aren’t linked gangs or terrorism can no longer ask government immigration attorneys to postpone their deportation proceedings in order to focus on deporting undocumented immigrants who actually present a security threat.

This change is the direct result of an executive order Trump signed on Jan. 25, and it could potentially tee up the deportations of hundreds of thousands of law-abiding undocumented immigrants. Initially, Trump administration officials indicated they would keep enforcing immigration laws in a similar way. In his first White House press briefing, press secretary Sean Spicer told reporters that the Trump administration will prioritize deporting undocumented immigrants who have criminal convictions.

That appears to no longer be the case.

Matthew Kolken, an immigration attorney who is based in Buffalo, said he has about a dozen clients who have requested prosecutorial discretion to temporarily postpone their deportation proceedings. He said the change in Buffalo means it is now much harder for those clients to stave off deportation

“It’s a big deal,” said Kolken, who frequently represents undocumented children. “Basically, it’s full steam ahead for deportations.”

For immigration attorneys trying to keep their clients from being deported, the abrupt and dramatic change is confusing.

“The way I’ve been hearing it phrased is, they’ve been asked to take a temporary pause in processing any sort of requests for prosecutorial discretion,” said Elizabeth Dobosiewicz, an immigration attorney and liaison with ICE on behalf of the Upstate New York Chapter of the American Immigration Lawyers Association. “We’re not really sure what the scope of that means.”

Reached for comment by The Daily Beast, the ICE field office in Buffalo would not confirm or deny the moratorium on prosecutorial discretion. An ICE official who spoke on background said that the agency itself hadn’t put a moratorium on the use of prosecutorial discretion. But that hasn’t stopped local ICE offices from stopping the practice on their own.

And it’s not just Buffalo.

Heather Drabek Prendergast, who chairs the American Immigration Lawyers Association’s ICE Liaison Committee, told The Daily Beast that different ICE offices are reacting to the executive orders in a variety of different ways. Some ICE field offices are still accepting requests for prosecutorial discretion, she said.

“I’ve heard reports from other offices that their attorneys are being told that there’s a moratorium on prosecutorial discretion, and no decisions are being issued,” she said. “And then we’ve heard from other of a couple of offices that have taken kind of an extreme approach––and not necessarily the office itself, but more like rogue agents out in the field who are interpreting the executive orders quite literally, without any actual guidance regarding what should be done to line up with those enforcement priorities. So it’s really kind of across the board.”

And, she added, that’s because the Department of Homeland Security hasn’t told them how to comply with the executive order.

“I think it’s confusing for everyone,” she said. “It’s a fluid situation. It’s changing literally throughout the day in each jurisdiction.”

Trump’s order effective reverses the Obama policy on immigration enforcement. That policy, detailed in a November 2014 memo, prioritized the deportation of undocumented immigrants who had been convicted of serious crimes or who threatened national security.

The rationale was that since the federal government has limited resources, it might as well find a way to concentrate on deporting dangerous people.

Now that some ICE field offices have stopped using “prosecutorial discretion,” that may no longer be the case. For the time being, some of those field offices seem to be assuming the executive order means a crackdown on all undocumented immigrants––not just those convicted of serious crimes.

That said, this could change. The Department of Homeland Security––which handles immigration enforcement––is currently a disorganized mess, thanks to the Trump administration’s poorly organized transition process. So Immigration and Customs Enforcement field offices have had to figure out on their own how to comply with Trump’s immigration executive orders. Until Secretary of Homeland Security John Kelly sends more direction to ICE field offices on how to understand and implement Trump’s executive order, different ICE offices will try to figure out on their own what exactly the president’s executive order means.

Kolken said it’s possible the end of prosecutorial discretion will become a national policy, and a permanent one––fast-tracking deportations for the hundreds of thousands of immigrants currently waiting for their day in court. And Kolken said this is a central part of Obama’s legacy on immigration.

“He handed him half a million deportations on a silver platter,” he said, referring to the 530,000+ backlog of cases in immigration courts. “He cooked the turkey and left it for Trump to carve up.”