() Federal workers aren’t guaranteed back pay for their mandated time off when furloughed, according to a White House memo obtained by Axios.

The memo from the Office of Management and Budget hinges on an interpretation of the Government Employee Fair Treatment Act of 2019, an administration official confirmed to partner The Hill. The memo came as the federal government shutdown hit one week on Tuesday.

Trump signed the 2019 law during the last government shutdown, which lasted for 35 days amid opposition for his border wall project.

Citing a line in the amended version of the law, the OMB memo makes the argument that furloughed employees only get back pay “subject to the enactment of appropriations Acts ending the lapse.”

Current guidance from the Office of Personnel Management maintained last month that furloughed employees are entitled to “retroactive pay” for the periods.

Trump on furloughed worker pay: ‘Depends on who we’re talking about’

When asked whether furloughed workers should be given back pay after the shutdown ends, Trump said Tuesday that it “depends on who we’re talking about.”

“For the most part, we’re going to take care of our people,” Trump said. “There are some people that really don’t deserve to be taken care of, and we’ll take care of them in a different way.”

At least 580,000 federal workers could be furloughed during the shutdown, according to estimates based on public personnel data.

Last week, White House press secretary Karoline Leavitt confirmed that layoffs and firings could reach thousands if the stalemate continues.

“We don’t like laying people off. Nobody takes joy and if you think that, that’s very sad you view the White House and our staff as wanting to put people out of work. Nobody wants to do that, but sometimes in government, you have to make the tough decisions,” Leavitt told Mary Bruce of ABC News.

Opposition has already started for the memo. Sen. Patty Murray, D-Wash., called it a “baseless attempt” to scare workers by an administration she believes is “run by crooks and cowards.”

“The letter of the law is as plain as can be federal workers, including furloughed workers, are entitled to their back pay following a shutdown,” Murray said.

‘s Anna Kutz contributed to this report.