As Washington dickers over raising the debt limit, the White House is offering a sober take on the real-world impact of default.

If lawmakers fail to raise the federal debt limit before the government runs out of money to cover its bills, it could set off a global financial crisis that the United States would be powerless to confront, White House economists warn in a report released on Wednesday.

“A default would send shock waves through global financial markets and would likely cause credit markets worldwide to freeze up and stock markets to plunge,” officials at the White House Council of Economic Advisers warned. “Employers around the world would likely have to begin laying off workers.”

The potential for an ensuing global recession, they wrote, could be worse than the 2008 financial crisis, because it would come as countries continue to struggle to escape the Covid-19 pandemic. Adding to the burden, Congress and President Biden would be unable to spend money to prop up the economy until the debt limit, which caps the amount that America can borrow, is raised.

“The federal government could only stand back,” they wrote, “helpless to address the economic maelstrom.”

Mr. Biden and Democratic leaders in Congress are engaged in an escalating standoff with Senate Republicans, who agree the debt limit must be raised in the coming weeks to avoid default, but who are blocking an up-or-down vote to do so. The Republicans want Democrats to use a special process in the Senate to bypass their filibuster, which Democrats have resisted. Mr. Biden has called the Republicans’ actions irresponsible and tried, and failed, to shame them into allowing a vote.

The report released on Wednesday offered a detailed and near-apocalyptic rundown of White House fears of how a default on the debt — which would come when the government is unable to pay everyone it owes money to at once — would ripple through the economy.

The officials warn that even the threat of a default in 2011 pushed up mortgage rates for home buyers for months, and that an actual default could elevate them even further this time. They also say retirees, Medicare beneficiaries, members of the military and millions of other people who depend on federal payments could see their means of support cut off “quickly, even overnight in some cases.”

They also say some critical federal services — like forecasts from the National Weather Service or time keeping from the National Institute of Standards and Technology — could be disrupted for lack of funds.

Mr. Biden is continuing to press Republicans to allow Democrats to approve a debt-limit increase along party lines in the Senate. Barring that, Democrats in Congress will be forced to move the increase through the budget reconciliation process that bypasses a filibuster, or move to eliminate the filibuster for the vote.

The administration has ruled out unilateral efforts to bypass the limit, like minting a $1 trillion coin, saying such efforts would sow uncertainty that would damage the economy.