WASHINGTON, United States (AFP) — US President Donald Trump warned Thursday that a government shutdown was looming, as the White House raised the stakes in a clash with Democrats by threatening mass federal firings.

Republican Trump is in a tense showdown with congressional Democrats to agree on spending plans ahead of a fiscal deadline of midnight on 30 September, after which key services will be cut.

“Could be, yeah,” Trump told reporters when asked in the Oval Office if a shutdown was likely. “Because Democrats are crazed, they don’t know what they’re doing.”

The White House earlier ordered government agencies to prepare for layoffs that would go beyond the usual practice of temporary furloughs during government shutdowns.

In a memo obtained by Agence France-Presse, the White House Office of Management and Budget told federal agencies to “use this opportunity to consider Reduction in Force (RIF) notices for all employees.”

The move would add to the pain of government workers after large-scale firings masterminded by tycoon Elon Musk’s Department of Government Efficiency earlier this year.

Democrats have rejected Republican proposals, unless some of the spending cuts are reversed and existing health care subsidies are extended.

Democratic House Minority Leader Hakeem Jeffries responded to threat of layoffs by telling the White House to “get lost.”

“We will not be intimidated,” he told reporters, describing OMB chief Russ Vought as “totally and completely out of control.”

“The Trump administration has made their intention clear: They want to continue to fire the civil servants who are hard-working American taxpayers.”

‘Insane demands’

A shutdown would see non-essential operations grind to a halt and hundreds of thousands of civil servants temporarily left without pay.

But the White House memo also ordered agencies to submit proposed staff reduction plans, and to inform employees.

It blamed “insane demands” by Democrats and accused them of breaking what it called a 10-year trend of reaching bipartisan agreement to avoid shutdowns at the same time of year.

Shutdown battles have become a regular feature of US politics under both Republican and Democratic administrations in an increasingly paralyzed and polarized Washington.