WASHINGTON, D.C. — Three Republican senators are threatening to block a gun safety fix that’s been eagerly embraced by most of Washington’s power players.

Sens. Rand Paul, Mike Lee and John Kennedy oppose the current version of Sen. John Cornyn’s bid to improve the accuracy of existing background check systems for firearm purchases. President Donald Trump reiterated his support for the plan Monday.

Kennedy, R-La., told McClatchy on Monday that the U.S. needs “more idiot control, not more gun control.”

Trump on Monday cited Cornyn’s bill as among the steps he wants to take in the wake of the deadly Valentine’s Day mass shooting at a Florida high school. Also backing the measure are Senate Majority Leader Mitch McConnell, House Speaker Paul Ryan and the National Rifle Association.

But it takes 60 Senate votes to get legislation moving, and the three senators are eying strategies to delay, dramatically modify and even kill the current bill. So far, the measure is not on the Senate schedule.

Trump on Monday suggested changes, saying the bill would be “strengthened” and made “more pertinent” to the school shooting.

“We need strong background checks,” he said at a White House meeting with the nation’s governors. “For a long period of time, people resisted that. But now people, I think, are really into it.”

First proposed in November after the largest mass shooting in Texas history, the legislation does not expand background checks to more purchases, but rather requires state and federal officials to do a better job of reporting relevant legal and mental health details to the national instant background check system.

The shooter in a Sutherland Springs, Texas, church, killed 26 people with a firearm he purchased after passing a background check, despite multiple military and domestic violence complaints. The bill would increase federal funding for reporting domestic violence records to the national background register.

Kennedy, Lee and Paul said they agree the National Instant Criminal Background Check System, known as NICS, needs to be improved.

But they said the current version of Cornyn’s bill does not provide enough due process to those who land on the list, including some military veterans who they said would be automatically reported to the system.

The senators warned that providing incentives, such as federal grant preferences, to state and federal agencies for reporting “might lead to an increase in the likelihood of abuse and administrative error.”

Without changes, the three wrote in a letter to Republican colleagues, the legislation “would encourage future administrative agencies to encroach upon constitutionally guaranteed rights without affording robust due process protections.”

They warned that “if Republican leadership wishes to move forward,” the legislation would need to include a right to an appeal in a court “prior to any denial of Second Amendment rights.”

A spokesman for Lee said Monday that there have been staff-level discussions among those interested in the bill about the three senators’ concerns.

The House passed a version of the legislation in December, but it was attached to concealed-carry legislation, which would go nowhere in the Senate, with its 60-vote requirement to advance legislation. Nineteen House Republicans are asking House Speaker Paul Ryan to take up the background check measure by itself.

The Gun Owners of America in December opposed the legislation, calling it additional gun control.

“We’re very concerned that more law-abiding people are going to be thrown into the NICS system,” Erich Pratt, executive director of Gun Owners of America said at the time. “It’s a broken system; we don’t want to fix it, we want to fix it for good by repealing it.”

At least 15 Senate Democrats have co-sponsored the background check legislation, but Senate Minority Leader Chuck Schumer, a co-sponsor, said Monday that its effect would be minimal.

“It is our hope that Republican leaders will help pass real legislation that makes a difference, rather than NRA-backed bills that make Republicans feel better without meaningfully addressing the issue of gun safety,” Schumer said. “We can’t afford a bill that is simply aimed at pleasing the NRA but doesn’t get the job done, we need real results.”