WASHINGTON -- The US Senate on Thursday failed to advance competing Democratic and Republican health care bills, which means over 20 million people could face much higher premiums because the expanded subsidies for the Affordable Care Act (ACA) are set to expire at the end of the month.

Four Republicans joined Democrats to back a three-year extension of the COVID-era enhanced subsidies, but the proposal fell short of the 60 votes needed to break a filibuster. A Republican proposal to expand health savings accounts as an alternative to the expiring tax credits also failed to garner enough support.

Thursday's Senate votes were part of an agreement that Senate Majority Leader John Thune reached with Democrats to end a record 43-day government shutdown, which ended on Nov 12.

At that time, some Democrats voiced discontent with the deal, particularly over the uncertainty surrounding health care benefits.

The latest development drew strong criticism from Democrats. "Instead of lowering premiums, Republicans chose instead to rip away healthcare funding, kick millions off insurance, and close rural hospitals. Why? So they could give their billionaire buddies a tax break," Senate Minority Leader Chuck Schumer said on X.

The Affordable Care Act, commonly known as Obamacare, has about 24 million enrollees, 22 million of whom are eligible for enhanced subsidies that help lower their premiums.