Conflict over Common Core, the widely adopted national math and language arts standards, spiked Wednesday as opponents brought their concerns to the state Capitol while backers countered with a campaign to support the continued rollout.

Outside, a group of self-described “moms” from across the state gathered to share their opposition to the standards that were introduced in most public school classrooms last fall.

Inside, state Sen. Vicki Marble, R-Fort Collins, touted her “Colorado Moms’ Bill” — Senate Bill 136 — that would delay new statewide tests for a year pending a review of the standards. The proposal is scheduled to be heard in the Senate education committee on Thursday afternoon.

“Common Core was developed using a top-down approach,” Marble said. “It was pushed onto Colorado with too little debate and no parental input. …We want to keep our education decisions local.”

A few hours earlier, a collection of Common Core backers from a coalition of nonprofit organizations sought to head off any uneasiness over the changes as nationwide controversy gains momentum.

They sponsored a panel discussion for legislators that traced the roughly seven-year history behind development of the new Colorado Academic Standards, which cover 10 subject areas including Common Core math and language arts benchmarks.

The panelists, Lt. Gov. Joe Garcia plus two teachers and a member of the business community, stressed that Common Core doesn’t dilute state standards or inhibit local control of curriculum, and that new assessments won’t impact recently instituted teacher evaluations as some fear.

State Rep. Carole Murray, R-Castle Rock, noted afterward that in a time of tremendous change in education, Colorado shouldn’t back off its expectations for student performance.

“I want to put the gas on,” Murray said, “because we’re losing kids every day that we try to put the brakes on. In my mind, slowing down is not an option.”

But Marble wasn’t swayed by the panel, she said, because she has heard from so many parents and teachers concerned about loss of local control and adopting untried standardized tests.

Colorado became part of a multi-state testing consortium called PARCC — Partnership for Assessment of Readiness for College and Careers — that is creating assessments to measure student progress in the new standards.

This spring, students will take state-generated tests in science and social studies. Next school year, they will see pilot PARCC tests aligned to Common Core math and language arts standards. The testing issue has been contentious in several states, as some have pulled out of testing consortiums and sought alternatives.

“We’re defining education in terms of assessment,” Marble said. “We may disagree on why Common Core isn’t right for Colorado this year, but we all agree that this process has moved too fast with too little input from Colorado’s educators and parents.”

Marble introduced supporters, including two charter school administrators, who criticized the methodology of the new state tests, which are designed to be taken on computers, as well as the time and money they would divert from their schools’ regular instruction.

“Ultimately, it’s our belief that content standards at a national level will drive conformity instead of innovation, and mediocrity instead of excellence,” said Wes Jolly, director of academic services for The Classical Academy, a Colorado Springs charter school. “We as a state can do better.”

Opposition to Common Core has emerged in several states recently, a backlash fueled by a wide variety of concerns across the political spectrum. Those range from general charges that the standards represent a federal takeover of education to complaints about new, untested assessments to worries that the Common Core advances a curriculum that, depending on point of view, is either too difficult or not tough enough.

Although Common Core, adopted in 45 states plus the District of Columbia, was developed by the National Governors Association and the Council of Chief State School Officers, it has been criticized as essentially a federal initiative in part because states that adopted it were looked on more favorably when it came to handing out millions in Race to the Top dollars.

And while it is a set of grade-level expectations, not a curriculum, critics point out that it comes with high-stakes student testing — assessments that, in many states including Colorado, will be linked to teacher evaluations. They add that teachers will naturally teach to the test, effectively making Common Core a de facto curriculum.

In Colorado, however, the department of education has guided a statewide, teacher-driven effort to produce sample curricula that address the new standards. The samples provide starting points that teachers can adapt with their own ideas to fulfill the needs of their particular district.

Jessica Cuthbertson, who teaches seventh-grade language arts at the Vista PEAK Exploratory school in Aurora and was part of the panel that spoke with lawmakers, disputes the notion that Common Core inhibits local control of curriculum.

“I’ve never had more autonomy as a practitioner,” she said.

The yet-to-be-named coalition of organizations that support the Common Core, convened by the Rose Community Foundation, also includes the Colorado Children’s Campaign, Colorado Succeeds and Stand for Children Colorado — groups that supported creation of tougher state standards as far back as 2007.

The legislature passed the bipartisan Colorado’s Achievement Plan for Kids — dubbed CAP4K — in 2008 and the following year the state department of education began rewriting standards in 10 content areas. In 2010, Colorado adopted the Common Core standards in math and language arts by a 4-3 vote of the state board, enticed partly by the promise of federal funding. They were embedded in what is now called the Colorado Academic Standards.

This school year, students and their families are seeing classroom changes triggered by Common Core, things like a greater emphasis on nonfiction texts and new approaches to math. It’s not surprising that some of the shifts have raised concerns, said Reilly Pharo, vice president of education initiatives for the Colorado Children’s Campaign who has been involved in launching the informational counterattack.

“I’m not fearful we’re going to see a major rollback as result of this legislation,” said Pharo. “But I do think the more time we spend intentionally talking about this work that happened over the last five years, the better for a broader audience around the state.”

Kevin Simpson: 303-954-1739, ksimpson@denverpost.com or twitter.com/ksimpsondp