A deal struck by the top Democrats and Republicans in the United States Senate to help raise the federal government's $28.9 trillion debt limit will be put to the test Thursday when the chamber votes on the measure.

The House of Representatives approved an unusual bill on Tuesday, agreed to by Senate Majority Leader Chuck Schumer and Minority Leader Mitch McConnell, to circumvent the Senate's "filibuster" rule and eventually increase federal borrowing authority by a simple majority vote.

The Senate is scheduled to hold a procedural vote on whether to advance the bill at 12:30 p.m. EST (1730 GMT). According to a party aide, it is likely to have enough Republican support to meet the 100-seat chamber's 60-vote threshold for most legislation.

“I’m optimistic that after today’s vote we will be on a glide-path to avoid a catastrophic default,” Schumer said in a speech to the Senate.

Republicans on track to dash Democratic hopes of US Senate majority –  EURACTIV.com

The Schumer-McConnell debt-ceiling agreement is embedded in legislation that would avoid cuts to Medicare, the government's health-care program for the elderly, which has broad bipartisan support.

The agreement comes just two months after Congress agreed to a temporary increase in the debt ceiling in order to avoid an unprecedented default by the federal government on its obligations, which would have disastrous consequences for the global economy.

Republicans have been attempting to hold off on voting for increased borrowing authority, claiming that doing so would pave the way for President Joe Biden's $1.75 trillion "Build Back Better" domestic investment bill, which they oppose.

Treasury Secretary Janet Yellen has urged Congress to act by December 15, and the Bipartisan Policy Center warned last week that if Congress does not act, the government could default by late this month.

Democrats pointed out that they had previously voted to authorize debt ceiling increases to cover Republican measures such as the Trump tax cuts.