• Members of Congress may be getting an up to $6,600 raise this year.
• That's due to a provision in a must-pass funding bill that's set to get a vote this week.
• Rank-and-file lawmakers have been making $174,000 since 2009.

For the first time since 2009, members of Congress may be about to get a raise.

Under a provision tucked into a new bill to fund the government through March 14, lawmakers would be given a cost of living adjustment to their salaries — something that Congress has blocked every year for a decade and a half.

That could result in up to a $6,600 raise for rank-and-file members of Congress next year, according to a recent report from the Congressional Research Service.

Currently, most members of the House and Senate make $174,000 each year. Some congressional leaders make more than that, such as House Speaker Mike Johnson, who makes a $223,500 annual salary.

Though that $174,000 sum is well above the average household income, it hasn't kept place with inflation, and lawmakers in both parties have argued that it's not enough to keep up with the demands and responsibilities of the job, which can include maintaining two residences.

"If we want working class people who don't rely on independent wealth, to represent people in Congress, we have to make it work," Democratic Rep. Alexandria Ocasio-Cortez of New York told Business Insider earlier this year.

"You have quite a number of members of Congress that sleep in their offices," Republican Sen. Mitt Romney of Utah told BI earlier this year. "In this day and age, it makes sense to have people that feel that they can serve, and still be able to sleep in a home at night."

If Congress hadn't blocked annual cost of living adjustments since 2009, rank-and-file lawmakers would be making $217,900 this year, according to the Congressional Research Service.

Earlier this year, a group of current and former lawmakers filed a class-action lawsuit to recover money that they would have made if their wages hadn't, in their view, been "unconstitutionally suppressed."

Increasing lawmakers' salaries has long been politically unpopular, and the inclusion of the provision is already leading to some opposition from more politically vulnerable members.

Rep. Jared Golden, a Democrat who represents a GOP-leaning district in Maine, said in a statement on Wednesday that he wouldn't vote for the government funding bill unless a pay freeze was reinstated.

"Members of Congress earn more than 90 percent of Americans," Golden said. "If any of my colleagues can't afford to live on that income, they should find another line of work."

If Congress fails to pass the bill by Friday, the federal government will shut down due to a lack of funding.