International Desk

A US judge on Thursday ordered six federal agencies to rehire thousands of probationary workers fired as part of Donald Trump's push to slash the size and scope of government.

The ruling is the latest judicial setback for the administration, coming on the heels of a string of legal defeats that nevertheless seem not to have slowed the pace of change.

Judge William Alsup said the justification of "poor performance" for mass lay-offs last month was "a sham in order to try to avoid statutory requirements," the New York Times reported.

Ruling on a lawsuit brought by employee unions, Alsup ordered the departments of the Treasury, Veterans Affairs, Agriculture, Defense, Energy and Interior to reinstate anyone on probation who was improperly fired.

"It is a sad day when our government would fire some good employee and say it was based on performance when they know good and well that's a lie," said Alsup at a hearing at the US District Court in San Francisco.

Since returning to the White House in January, Trump has taken an ax to the US government, cutting spending programs and firing tens of thousands of the more-than 2 million employees on the federal payroll.

His actions have faced pushback from the courts, with several judges issuing injunctions intended to halt them.

Last month Alsup ordered the federal government to rescind directives that resulted in thousands of staff being let go.

On Thursday, he said the government was within its rights to downsize staffing, but that it had to be done properly and with justification -- he cited "reduction in force" orders issued by several agencies as legal routes.

"If it's done right, there can be a reduction in force within an agency, that has to be true," he said.

"Congress itself has said you can have an agency do a reduction in force, if it's done correctly under the law."

But that was not the case with the orders issued by the Office of Personnel Management (OPM) -- the government's human resources body -- whose actions amounted to overreach.

Attorneys from the Justice Department, representing the Trump administration, had insisted that OPM never issued any orders, only guidance, the Washington Post reported.

But, the paper said, court records showed officials from agencies including the IRS, the Department of Defense, and Veterans Affairs, had disputed this, claiming the order to cut probationary workers came directly from the OPM.

Trump -- supported by a chainsaw-wielding Elon Musk -- has set about fundamentally reshaping the US government in a way that he says will make it leaner and more efficient, but which opponents say amounts to a bid to undermine its very purpose.

That effort found its latest expression this week when the Education Department said it was halving the number of staff, in what the Secretary of Education described as the first step to shutting it down.

Despite the high stakes, Trump faces few obstacles from the Washington political establishment.

The Democratic Party are still in disarray after their electoral drubbing and his Republican Party appears largely content to cede Congressional power to the executive.