Congressional lawmakers are scrambling to address the looming rise of health insurance premiums.

Four congressional Republicans joined Democrats signing a petition to force a vote on funding for the Affordable Care Act.

If the enhanced health care tax credits do expire as expected, insurance costs are expected to double, on average, for about 22 million people who get their coverage through the Affordable Care Act.

Around 1.5 million Californians receive their coverage through Covered California which is the state’s marketplace.

“Unfortunately, if we don’t see action from Washington D.C., we do anticipate to see people as many as 400,000 leave Covered California because they can no longer afford the price,” said Jessica Altman, Executive Director at Covered California.

The ACA funding bill is not expected to come to the floor before the Dec. 31 deadline, meaning the subsidies will expire.

Congressional lawmakers are expected to return to Washington on Jan. 6, meaning the vote on a three-year extension will likely happen mid-January.

If it passes, it will still need to clear the U.S. Senate.

Federal lawmakers in Washington D.C. have only days left to come to an agreement on health care costs before insurance premiums soar for millions of Americans.