A measure to implement Colorado’s new open primaries cleared the Colorado Senate and a House committee in rapid succession Monday, after lawmakers reached a late deal tweaking a controversial provision that would ask independent voters to declare a party preference.

With the changes, the path now seems clear for Senate Bill 305 to become law. But it would retain a few key, disputed pieces from the original measure: unaffiliated voters still will be asked before the election if they prefer one party’s ballot to the other, and the party primary they choose to vote in still will be a matter of public record.

When the measure was introduced, it immediately was assailed by supporters of open primaries, including the Denver Metro Chamber of Commerce and Let Colorado Vote, who complained that it would undermine what Colorado voters intended when they passed two ballot measures opening the state’s party primaries to unaffiliated voters.

At issue is whether election officials should be able to track unaffiliated voters by which primary they participate it, much as affiliated voters register with one party or another. State elections officials and the two political parties argue that voters have to be tracked by party to ensure the integrity of the two primary elections, while county clerks and backers of open primaries say it isn’t necessary.

“By declaring a preference, you really become an affiliated voter,” said Kelly Brough, CEO of the Denver Metro Chamber of Commerce. “I don’t think that’s what voters said they wanted in November.”

Under the amendment adopted Monday, voters still would be asked if they wanted to vote in one party’s primary or the other, said Sen. Steve Fenberg, D-Boulder, one of the bill’s sponsors. But unlike the original bill, that preference would last only for a single election cycle, a concession to opponents who felt that the initial process amounted to “de facto affiliation” of unaffiliated voters.

Under the changes, unaffiliated voters would be offered their choice of ballots again prior to each new primary election. Those who don’t indicate a preference will be sent one ballot for each party and be instructed to vote in only one.

The organized opposition to the measure evaporated after the amendment’s adoption, but many of the concerns remain. Under the bill, the state still would record which party primary independents vote in.

Let Colorado Vote, the group that backed the ballot initiative, said in a statement that it was pleased the “most egregious” provisions of the bill had been taken out.

“We will continue to seek an expansion of Colorado’s confidential voter laws to include voters who, for personal or professional reasons, do not want to have their primary participation included in public voter registration records,” said Jason Bertolacci, a spokesman for Let Colorado Vote.

The Senate approved the bill 31-4, with wide bipartisan support. It cleared the House Finance Committee unanimously the same afternoon and moves to the House floor on a tight timeline. The session ends Wednesday.

Earlier in the day, House and Senate lawmakers negotiated a compromise on a measure that gives political committees 15 business days to fix any mistakes on campaign finance forms without penalty after a complaint is filed. Under current law, the committees can face a $50 per-day sanction.

The final version still allows fines if an administrative law judge finds the committee did not substantially comply with the law. If the two chambers agree to the changes, it would go to the governor for his signature.

Staff writer John Frank contributed to this report.

Correction: An earlier version of this story incorrectly characterized the effect of an amendment. Unaffiliated voters would still be asked if they wanted to vote in one party’s primary or the other, but unlike the original bill, that preference would last only for a single election cycle.