Gov. Spencer Cox rushed to sign into law language tacked onto a bill an hour before legislators adjourned Friday night that could torpedo efforts to keep a Republican-led effort to restore the Legislature’s ability to gerrymander political districts off the ballot.

Thousands of voters have submitted forms to their county clerks to remove their names from petitions for an initiative to repeal a voter-approved 2018 ballot measure that banned partisan gerrymandering.

But the new provision, which Cox signed less than 12 hours after it passed the Legislature, prohibits county clerks from accepting removal forms that were mailed in an envelope with pre-paid postage. Unlike most bills which go into effect later this year, the stamp prohibition received two-thirds support from the Legislature — all from Republicans — and is in force following the governor’s approval.

For more than a month, Better Boundaries has been mailing the removal forms, already filled in with voters’ information, to everyone who signed the petition, encouraging them to sign the form and return it to their clerks in a pre-stamped envelope.

The Republican backers of the repeal effort sued, contending the stamp essentially constituted an illegal bribe, inducing voters to rescind their signatures and asking a judge to disqualify forms received with pre-paid postage.

Now, with the law immediately changed, clerks are prohibited from accepting any forms with pre-paid postage that were not postmarked by Friday, meaning voters will have to pay for their own stamp or go to their county clerks’ offices to remove their signatures.

“The Legislature has once again changed the rules for their own benefit midway through the process at the expense of everyday Utahns,” said Better Boundaries executive director Elizabeth Rasmussen. “This bill was obviously planned to pass as the clock ran out with little public input. This type of legislative behavior is what happens when there’s no check on your power.”

There was almost no discussion of the change, which was dropped into the legislation at 11 p.m. on the final night of the session. While it typically takes several days or weeks for a bill to be signed into law, it was sent to the governor at 2:16 a.m. and signed hours later.

There was no debate on the bill, aside from Sen. Nate Blouin, D-Millcreek, who rose to say, “What this is doing is directly impacting the effort to overturn Prop 4 now. I want to put that on the record.”

A spokesperson for the governor did not respond to a request for comment, nor did the sponsors of the bill, Sen. Brady Brammer, R-Pleasant Grove, who added the language banning pre-paid postage, or Clinton Republican Rep. Karen Peterson.

The repeal effort of the Republican-led Utahns for Representative Government appears to comfortably have enough signatures to qualify for the ballot.

In order to make it on the ballot, UFRG needs to meet certain signature thresholds in 26 of Utah’s 29 Senate districts — which it has currently done.

To prevent the anti-gerrymandering repeal from making it to voters, opponents need to rack up enough removals to knock just one district below the target.

The margin initially was razor-thin, but Davis County identified numerous signature packets that had been disqualified because, according to Davis County Clerk Brian McKenzie, the first signature on the packet showed the year 2025 instead of 2026. With those signatures counted, the repeal effort has a cushion of at least 750 signatures in the critical senate districts it needs in that county.

Now, the district closest to falling under is Senate District 12, where opponents would need 571 more removals, based on Friday’s data from the lieutenant governor’s office. Rasmussen said Better Boundaries is continuing its efforts, and the group Brave Utahns Rapid Response Network held a “Signature Removal Party” Saturday at two Cottonwood Heights locations, which are part of Senate District 12. Organizers said volunteers planned to hand-deliver forms to the Salt Lake County Clerk’s office.

If the UFRG initiative makes the ballot, voters will decide whether to repeal Proposition 4 — which created an independent redistricting commission, established neutral redistricting criteria and prohibited manipulating boundaries to favor one party and disadvantage the other.

It would not impact the map in place for the 2026 congressional race, but would allow the Legislature to redraw the maps for the 2028 election without the Proposition 4 limitations.