A judge paused a scheme masterminded by billionaire Elon Musk to slash the US government by encouraging federal workers to quit through a mass buyout by midnight Thursday.

The federal judge in Massachusetts ordered a temporary injunction on the deadline given by Musk for the country's more than two million government employees to quit with eight months' pay or risk being fired.

The deadline is now extended to Monday when US District Judge George O'Toole will hold a hearing on the merits of the case brought by labor unions, US media reported.

Musk, the world's richest person and President Donald Trump's biggest donor, is in charge of a free-ranging Department of Government Efficiency (DOGE) that aims to radically downsize federal agencies.

According to White House Press Secretary Karoline Leavitt, more than 40,000 staff have so far accepted the buyout deal — a relatively small number.

Unions representing some 800,000 civil servants and Democratic members of Congress are resisting the scheme and have challenged the legality of threats to fire civil servants.

But the campaign — fanned by anti-government-worker invective from Trump and his aides — has already severely disrupted the huge departments and agencies that for decades have run everything from education to national intelligence.

USAID, the government's agency for distributing aid around the world, has been crippled, with foreign-based staff ordered home and the organization's programs lambasted daily as wasteful by the White House and right-wing media.

Trump has also repeatedly said he wants to shut down the Department of Education. The inducements to resign have even been extended to the CIA.

In another sign of the scale of the intended cuts, an official with the agency that manages government property said the real estate portfolio, barring Department of Defense buildings, should be cut by "at least 50 percent."

Leavitt defended the onslaught, telling reporters that federal workers should "accept the very generous offer."

She said "competent" replacements would be found for those who "want to rip the American people off."

Among the controversies swirling around the Musk plan is how much access the South African-born tycoon is getting to secret government data, including the Treasury's entire payment system.

Treasury Secretary Scott Bessent told Bloomberg TV on Thursday that there was "a lot of misinformation" and that access to such data was only given to two Treasury employees who are working with Musk.

Bessent said those employees had "read-only" access, meaning they couldn't change the data.

'Chill' or big 'con'?

Workers considering the buyout offer face considerable uncertainty, including over whether Trump has the legal right to make the offer and whether the conditions will be honored.

The plan was first announced in an email sent across most of the vast government and titled "Fork in the road" — the same as one Musk sent to all employees at Twitter when he bought the social media platform in 2022 and renamed it X.

Musk says the paid departures are a chance to "take the vacation you always wanted, or just watch movies and chill, while receiving your full government pay and benefits."

Unions warn that without Congress signing off on the use of federally budgeted money, the agreements may be worthless. 

"Federal employees shouldn't be misled by slick talk from unelected billionaires and their lackeys," Everett Kelley, president of the large American Federation of Government Employees (AFGE).

"This deferred resignation scheme is unfunded, unlawful and comes with no guarantees. We won't stand by and let our members become the victims of this con."

The Massachusetts lawsuit also casts doubt on assertions that workers would be free to look for other jobs during their deferment periods, citing ethics regulations. 

An employee in the US Office of Personnel Management, where Musk has put his own staff in key positions, said the plan was to encourage resignations through "panic."

"We're trying to instill a panic so that people just walk out the door and leave government in a crippled state, which is partly their objective," the employee told AFP, speaking on condition of anonymity.