Opponents of Utah's school voucher law say they have collected more than enough signatures to put the act on hold until the public can vote whether to repeal it.

Utahns for Public Schools estimated Sunday night they had collected more than 130,000 signatures - nearly 30 percent more than they needed - and met the required 10-percent threshold in 24 of Utah's 29 counties, said communications director Lindsay Zizumbo.

A dozen volunteers worked late into the night counting signatures, photocopying and sorting petition booklets and checking voter rolls. The group will announce its best signature estimate at a Capitol news conference at 11:30 a.m. today. County clerks must receive all signature booklets by 5 p.m.

"We were told from the very beginning we couldn't do this" with volunteers alone, said Pat Rusk, a spokeswoman for the group and former president of the Utah Education Association. "But it was done solely from volunteers . . . we did not pay for any signatures."

An effort to repeal Utah's school voucher law began days after the 2007 Legislature adjourned. The "Parent Choice in Education Act" would let parents apply for private school tuition assistance from the state - from $3,000 for Utah's poorest families to $500 for its richest.

Opponents of the law had less than 40 days to collect 92,000 signatures, including at least 10 percent of voters from the 2004 gubernatorial election in at least 15 counties.

Once county clerks certify how many petition signatures belong to registered voters, the Lt. Governor's Office has until April 30 to count the valid signatures. If it rules the petition sufficient, Gov. Jon Huntsman will set an election date for the public to vote on a repeal.

Leaders at Utahns for Public Schools believe most people who signed the petition would vote to overturn the law.

Some citizens criticized volunteers, others asked questions before signing the petition and some asked to help gather signatures, Rusk said. Some counties were particularly tough, said Carmen Snow, president of the Utah PTA. She pointed to Washington County, home to two powerful legislators who strongly support vouchers.

But the group said signatures surpassed the 10-percent threshold in Utah County, where all 13 state representatives voted for the voucher law in the closely-divided House.

The petition effort wasn't without setbacks. Opponents questioned whether volunteers broke state laws by setting up petition tables at parent-teacher conferences and allowing school PTAs to send pro-petition fliers home with students. The pro-voucher Parents for Choice in Education contacted schools about proper procedures but has no current plans to file a legal challenge, said spokeswoman Nancy Pomeroy.

Most demoralizing for the referendum group, leaders said, was an opinion from the Utah Attorney General's office that a voucher program could go forward even if the referendum succeeds. The opinion said a second law, which amended the one targeted by the petition drive, could stand on its own to establish school vouchers.

Parents for Choice supports that finding, which agreed with one the group commissioned. Pomeroy declined to comment about the group's plans if the referendum drive succeeds.

Rusk and Utahns for Public Schools are bracing for an effort to disqualify signatures. They are photocopying petitions before submitting them, and working to independently verify registered voters. They're also organizing signature booklets numerically and plan to work with county clerks today to ensure all boxes of booklets are officially received.

"We're dotting all the I's and crossing all the T's so it will be very difficult to say we did something wrong," Rusk said.