A federal judge on Thursday paused the Trump administration’s deadline for more than 2 million federal employees to decide by the end of the day whether to resign or stay in their jobs in order to allow time for labor unions to challenge the plan’s legality.

U.S. District Judge George O’Toole in Boston issued a temporary restraining order and set a hearing for Monday.

The Trump administration’s lawyers had argued that extending the deadline on the very last day would “markedly disrupt the expectations of the federal workforce, inject tremendous uncertainty into a program that scores of federal employees have already availed themselves of, and hinder the administration’s efforts to reform the federal workforce.”

But after the judge issued his order, White House press secretary Karoline Leavitt said the administration was grateful for the extension “so more federal workers who refuse to show up to the office can take the administration up on this very generous, once-in-a-lifetime offer.”

Unions representing many of the nation’s federal workers charge that the new Republican administration’s “unprecedented offer” violates the law.

“We will continue to aggressively defend our members’ rights,” said Everett Kelley, president of the American Federation of Government Employees, one of the unions challenging the offer.

Workers were given barely more than a week to accept the administration’s blanket buyout, which union officials say did not appear to have followed federal procedures for reducing the size of the workforce.

Federal employees were told they would receive eight months of pay and benefits through September if they resign by Feb. 6.

But Congress hasn’t approved funding for federal agencies past March 14.

Unions have warned workers considering Trump’s offer that there’s no guarantee the president can or will stick to it. They’ve also said the offer lacks basic information about whether they might still be required to work for the government, whether they can get a private sector job while still being paid by the federal government and how their pensions, health insurance and other benefits and rights would be affected.