Sen. John Thune (R-S.D.), the chairman of the Senate Commerce Committee, raised a  prospect that could hobble the FCC later this year: The lack of a quorum.

The commission is currently split 2-1, with Republicans commanding a majority. There are currently two vacancies on the commission, and there is the prospect for one more. The term of Mignon Clyburn, the sole Democrat on the commission, expires at the end of June.

If the FCC were left with three vacancies, it would lack a quorum.

“The most important thing is that we don’t allow the FCC to fall below a functioning quorum,” Thune said at an oversight hearing on Wednesday. That’s why he urged the Senate to act quickly when President Trump nominates two others to fill vacancies — something that he has yet to do.

At the hearing, Thune asked Clyburn about the prospect that she would depart the commission before her term is up. That is something that would leave the agency unable to act on pending business, or any repeal of current net neutrality rules. Clyburn opposes a rollback of the FCC’s 2015 rules, which prohibit internet providers from giving preferential treatment to certain types of content.

“It has been suggested that you may be able to deny the FCC that quorum by either leaving before your term expires at the end of June, or refusing to attend open meetings,” Thune said. He then asked whether she would commit to serving out her term.

“What you read has never been suggested or hinted about me,” Clyburn said. “I’ve had no plans to do anything that would jeopardize the functionality of this institution that I love so much.”

Other dynamics also are in play when it comes to filling the remaining slots at the FCC.

Trump on Tuesday renominated Chairman Ajit Pai to another term at the FCC, meaning that he, too, will have to go through the confirmation process.

Yet Senate Democrats are upset that the GOP-controlled Senate never acted on the renomination of Jessica Rosenworcel to another term at the agency last year, allowing her tenure to lapse. Trump recently rescinded her renomination.

Sen. Bill Nelson (D-Fla.), the ranking member of the Senate Commerce Committee, called Trump’s action “unfortunate” and again criticized Republicans for not acting on Rosenworcel’s nomination.

Sen. Brian Schatz, a member of the Senate Commerce Committee, on Tuesday suggested that they would tie approval of Pai for another term to Rosenworcel’s return to the commission.

“We are still waiting for the renomination of Commissioner Rosenworcel, and that will determine how I and other Democrats on the committee are likely to handle all nominations including Chairman Pai’s,” he said.