A judge plans to rule Tuesday on the validity of a ballot question seeking to raise taxes for Colorado schools.
Opponents of Amendment 66 say they've identified enough suspect signatures on petition ballots to put the ballot measure in question. They made their case during a court hearing in Denver on Friday.
The school tax proposal has already been printed on ballots, but if the tax opponents prevail, votes on the ballot question won't be counted.
The measure would raise some $950 million a year.
Groups supporting the school finance overhaul delivered more than 160,000 signatures in August to the secretary of state. State elections officials said about 90,000 of those were valid. That's about 3,700 more than what's needed to get on the ballot.