A simmering debate among Senate Republicans about whether to embrace the return of earmarks will come to a head next week.

GOP senators are set to review the caucus rules next Wednesday. Though the review takes place every two years, it's the first opportunity the caucus will have to revisit a 2019 permanent ban on earmarks.

"Well, the conference meets every two years to go over all the conference rules. ... Currently our tradition is that we don't do earmarks. So people are going to be submitting any changes to the conference rules that they would like," said Sen. John Barrasso (Wyo.), who as chairman of the Senate GOP conference will oversee the discussion.

The debate over whether to formally greenlight earmarks is sparking deep divisions among Senate Republicans, who have hammered President Biden over his multitrillion-dollar spending proposals.

Conservatives are already firing warning shots to their colleagues, some of whom have said they will use earmarks to help direct funding back to their home states.

"Earmarks promote backroom deals that make lobbyists rich on the taxpayer's dime. They're a relic of the swampy politics that DC’s known for & one of the best things Congress did was get rid of them," Sen. Steve Daines (R-Mont.) tweeted.

Sen. Ted Cruz (R-Texas), who was first elected to the Senate as part of a Tea Party wave that focused on cutting spending, vowed that he would "fight against these corrupt denizens of darkness." And Sen. Pat Toomey (R-Pa.) said earlier Wednesday that he would not take part in the earmark process.

“I have no intention of participating in any earmark process and will continue to urge my Senate Republican colleagues to do the same,” he said.

The Senate GOP banned earmarks in 2010, with Democrats following suit in 2011, amid pressure from then-President Obama and House Republicans who, amid a rise in concern about the deficit, had homed in on the pet projects.

Senate Republicans also voted as a caucus in 2019 to permanently ban earmarks after a previous moratorium expired.

But they now find themselves as the odd man out on Capitol Hill, with Democrats in both chambers planning to revive earmarks and House Republicans voting this year to lift their own ban.

GOP members of the Senate Appropriators Committee are signaling they view the discussion next week as merely symbolic. Though the caucus rules include an earmark ban, another section states that the caucus rules are non-binding.

Sen. Shelley Moore Capito (R-W.Va.) said she intends to request earmarks, but that the rules currently allow each member to essentially make the decision for themselves.

"I mean, I think there is a rule that bans earmarks but there's also a rule that says we're not bound by the rules. So I don't know that there's going to be an effort to actually overturn or just clarify it. If people want to ... move forward with earmarks, they can. If they don't want to, they don't have to," Capito said.

She's backed up by Sens. Richard Shelby (R-Ala.) and Roy Blunt (R-Mo.), senior members of the Appropriations Committee, who say that Republicans who want to request earmarks will be able to even if the caucus agrees to keep the current ban in place during next week's meeting.

"If the goal here is to let every member do what they want to do, you wouldn't have to change the rules. And if you try to change the rules and it failed, it still wouldn't prevent everybody from doing what they wanted to do," Blunt said.

Shelby, asked about the current ban, said that “it doesn’t bind anybody.”

Opponents of earmarks point to language in the Senate GOP caucus rules that state that "it is the policy of the Republican Conference that no Member shall request a congressionally directed spending item, limited tax benefit, or limited tariff benefit" in legislation.

But top appropriators, who say that the ban isn't binding, point to a section stating no "action by the Conference upon any matter pending or to be proposed in the Senate shall be binding in any way on members in casting their votes thereon."

Sen. John Thune (S.D.), the No. 2 Senate Republican, suggested that whether the earmark ban is binding or merely symbolic would likely be a point of debate in next week's closed-door discussion.

"I think that's going to be part of the conversation. I don't know the answer to that, particularly with what the House did and what Democrats are going to do. I think that's what we're going to try to have to figure out," Thune said.

Barrasso similarly sidestepped whether the earmark ban is binding.

"We have a role set of conference rules that apply and anybody can come with an amendment," Barrasso said.

Asked about the argument that the ban is currently non-binding, he reiterated: "People can bring amendments to the conference and when we meet next Wednesday we'll have a chance to talk about all the rules."