The Senate and House have 12 joint working days before Sept. 29, when the Treasury Department says it would no longer be able to pay all of the government’s bills unless Congress acts. A default would likely set off a major disruption to the world financial system, with a stock market crash and surging interest rates that could send the economy into a recession.

Treasury Secretary Steven Mnuchin has urged Congress for months to raise the debt limit, but the White House has lacked a unified message and run into resistance on Capitol Hill, where Democrats and Republicans are at odds on key tax and spending issues.