President Donald Trump is making threats on congressional health insurance benefits, but the effort may face unexpected complications.

Trump tweeted Monday that the 2010 health care law is “hurting people,” and insurance companies and lawmakers should share in that pain. With respect to lawmakers, he asked, “why should Congress not be paying what public pays?”

This longstanding debate dates back to when the Office of Personnel Management determined in August 2013 that members of Congress and staffers could get employer contributions for the purchase of health insurance plans on the D.C. small business exchange under the 2010 law.

Champions of revoking the employer contributions through legislative action have been few and far between in Congress, though the leaders of the effort in the House and Senate joined Monday afternoon on a conference call to push for that.

Rep. Ron DeSantis, a Florida Republican, said he would want the primary effect of any change to fall on lawmakers themselves, rather than staffers on the exchange.

“People will say, ‘Oh, these people want to hurt the staff.’ We can raise our staff’s pay, so if this rule were repealed, I’d have to go to my staff and say, ‘OK, you know, maybe you guys all get a certain increase to make up for that,’” he said. “The staff can be remedied. There’s opposition really because the members can’t change their pay, and a lot of members don’t want to have to pay more.”

DeSantis also said that when it appeared previously that the Obama administration might not have resolved the issue, there was significant chatter around the House about the potential lost compensation.

“People were whispering about this in 2012 at the tail end when I came up as a member-elect, and then 2013: What are we going to do about this?” DeSantis said.

The leader of the effort in the Senate, Republican Ron Johnson of Wisconsin, said Monday he was serious about offering an amendment to the health care reconciliation package during the anticipated vote-a-rama to cut off employer contributions for members. He didn’t get the chance, because once the Senate voted down the “skinny” repeal of the health care law, Senate GOP leaders put the entire effort on the back burner.

Johnson said he brought his amendment up at Thursday’s Republican lunch and told colleagues he absolutely intended to force a vote during the vote-a-rama.

“In my amendment, I did exclude staff,” Johnson said. “I only wanted to put [members] in the same position. Staff, you know, again, I ran an organization. I want people who work for me to have health care, and I’m happy to give them an employer contribution. It’s members of Congress that are responsible for changing this law, for bringing down premiums.”

Johnson noted that, unlike his amendment, an administrative action would likely need to be more of a blunt instrument, also stripping the employer contributions away from congressional aides.

Beyond being unpopular on Capitol Hill, the latest round of presidential warnings come without a political appointee in place to execute such a policy change.

George Nesterczuk was nominated by Trump to helm the Office of Personnel Management in late May, and Democrats signaled as recently as July that he had not filed all the proper paperwork.

The nomination has not yet been taken up by the Homeland Security and Governmental Affairs Committee, which Johnson chairs.

In the absence of a Senate-confirmed director, the OPM has been run on an acting basis since the end of  the Obama administration by Kathleen McGettigan, a career federal employee.

John T. Bennett contributed to this story.