The US supreme court has cleared the way for Donald Trump's administration to resume plans for mass firings of federal workers that critics warn could threaten critical government services.
Extending a winning streak for the US president, the justices on Tuesday lifted a lower court order that had frozen sweeping federal layoffs known as "reductions in force" while litigation in the case proceeds.
The decision could result in hundreds of thousands of job losses at the departments of agriculture, commerce, health and human services, state, treasury, veterans affairs and other agencies.
Democrats condemned the ruling. Antjuan Seawright, a party strategist, said: "I'm disappointed but I'm not shocked or surprised. This rightwing activist court has proven ruling after ruling, time after time, that they are going to sing the songs and dance to the tune of Trumpism. A lot of this is just implementation of what we saw previewed in Project 2025."
Project 2025, a plan drawn up by the conservative Heritage Foundation thinktank, set out a blueprint for downsizing government. Trump has claimed that voters gave him a mandate for the effort and he tapped billionaire ally Elon Musk to lead the charge through the "department of government efficiency", or Doge, though Musk has since departed.
In February, Trump announced "a critical transformation of the federal bureaucracy" in an executive order directing agencies to prepare for a government overhaul aimed at significantly reducing the workforce and gutting offices.
In its brief unsigned order on Tuesday, the supreme court said Trump's administration was "likely to succeed on its argument that the executive order" and a memorandum implementing his order were lawful. The court said it was not assessing the legality of any specific plans for layoffs at federal agencies.
Liberal justice Ketanji Brown Jackson was the sole member of the nine-person court to publicly dissent from the decision, which overturns San Francisco-based district judge Susan Illston's 22 May ruling.
Jackson wrote that Illston's "temporary, practical, harm-reducing preservation of the status quo was no match for this court's demonstrated enthusiasm for greenlighting this president's legally dubious actions in an emergency posture".
She also described her colleagues as making the "wrong decision at the wrong moment, especially given what little this Court knows about what is actually happening on the ground".
Illston had argued in her ruling that Trump had exceeded his authority in ordering the downsizing, siding with a group of unions, non-profits and local governments that challenged the administration. "As history demonstrates, the president may broadly restructure federal agencies only when authorized by Congress," she wrote.
The judge blocked the agencies from carrying out mass layoffs and limited their ability to cut or overhaul federal programmes. Illston also ordered the reinstatement of workers who had lost their jobs, though she delayed implementing this portion of her ruling while the appeals process plays out.
Illston's ruling was the broadest of its kind against the government overhaul pursued by Trump and Doge. Tens of thousands of federal workers have been fired, have left their jobs via deferred resignation programmes or have been placed on leave.
The administration had previously challenged Illston's order at the San Francisco-based ninth US circuit court of appeals but lost in a 2-1 ruling on 30 May. That prompted the justice department to make an emergency request to the supreme court, contending that controlling the personnel of federal agencies "lies at the heartland" of the president's executive branch authority.
The plaintiffs had urged the supreme court to deny the justice department's request. Allowing the Trump administration to move forward with its "breakneck reorganization", they wrote, would mean that "programs, offices and functions across the federal government will be abolished, agencies will be radically downsized from what Congress authorized, critical government services will be lost and hundreds of thousands of federal employees will lose their jobs".
The supreme court's rejection of that argument on Tuesday was welcomed by Trump allies. Pam Bondi, the attorney general, posted on the X social media platform: "Today, the Supreme Court stopped lawless lower courts from restricting President Trump's authority over federal personnel - another Supreme Court victory thanks to @thejusticedept attorneys. Now, federal agencies can become more efficient than ever before."
The state department wrote on X: "Today's near unanimous decision from the Supreme Court further confirms that the law was on our side throughout this entire process. We will continue to move forward with our historic reorganization plan at the State Department, as announced earlier this year. This is yet another testament to President Trump's dedication to following through on an America First agenda."
In recent months the supreme court has sided with Trump in some major cases that were acted upon on an emergency basis since he returned to office in January.
It cleared the way for Trump's administration to resume deporting migrants to countries other than their own without offering them a chance to show the harms they could face. In two cases, it let the administration end temporary legal status previously granted on humanitarian grounds to hundreds of thousands of migrants.
It also allowed Trump to implement his ban on transgender people in the US military, blocked a judge's order for the administration to rehire thousands of fired employees and twice sided with Doge. In addition, the court curbed the power of federal judges to impose nationwide rulings impeding presidential policies.
On Tuesday the Democracy Forward coalition condemned the supreme court for intervening in what it called Trump's unlawful reorganisation of the federal government. It said in a statement: "Today's decision has dealt a serious blow to our democracy and puts services that the American people rely on in grave jeopardy."
"This decision does not change the simple and clear fact that reorganizing government functions and laying off federal workers en masse haphazardly without any congressional approval is not allowed by our Constitution."