The U.S. government shut down much of its operations on Wednesday as deep partisan divisions prevented Congress and the White House from reaching a funding deal, setting off what could be a long, grueling standoff that could lead to the loss of thousands of federal jobs.

There was no clear path out of the impasse, while agencies warned that the 15th government shutdown since 1981 would halt the release of a closely watched September employment report, slow air travel, suspend scientific research, withhold pay from U.S. troops and lead to the furlough of 750,000 federal workers at a daily cost of $400 million.

Trump, whose campaign to radically reshape the federal government is already on track to push out some 300,000 workers by December, warned congressional Democrats that a shutdown could clear the path for “irreversible” actions including cutting more jobs and programs.

The shutdown commenced hours after the Senate rejected a short-term spending measure that would have kept government operations afloat through November 21. Democrats opposed the legislation over Republicans’ refusal to attach an extension of health benefits for millions of Americans that are due to expire at the end of the year. Republicans say the issue must be addressed separately.

At issue on the government funding front is $1.7 trillion for agency operations, which amounts to roughly one-quarter of the government’s total $7 trillion budget. Much of the remainder goes to health and retirement programs and interest payments on the growing $37.5 trillion debt.

Independent analysts warn the shutdown could last longer than the budget-related closures of the past, with Trump and White House officials threatening to punish Democrats with cuts to government programs and the federal payroll. Trump budget director Russell Vought, who has called for “less bipartisan” appropriations, threatened permanent layoffs last week in the event of a shutdown.