An Ohio state bill which could allow students’ religious beliefs to trump science-based facts is almost identical to model legislation backed by an evangelical, anti-gay Christian group.

The Student Religious Liberties Act, which passed the Ohio house last week, instructs schools to neither “penalize or reward” students on the basis of their religious speech. It also stipulates schools must provide opportunities for religious expression “in the same manner and to the same extent” as secular speech. Critics argue the bill would provide protect students from bad grades based on religion.

The bill’s backers deny it is connected to the group, called Project Blitz but the bill has nearly identical language to the model legislation backed by Project Blitz in their 2018-19 “playbook”.

While student religious liberties bills existed before Project Blitz, its inclusion in a playbook by groups whose goal is to inject religion into law shows the priority they place on the matter. When contacted by the Guardian, Steven W Fitschen, president of the National Legal Foundation, said “We are, of course, delighted that legislators in Ohio drafted a bill so similar to our model bill since we believe its provisions are constitutional and beneficial to students of faith in Ohio, without impinging on anyone else’s rights.”

By contrast, many mainstream civil rights groups have lined up against the bill.

Project Blitz model legislation says: “A student may not be penalized or rewarded based on the religious content of his or her work.” The Ohio Student Religious Liberties Act says teachers “shall not penalize or reward a student based on the religious content of a student’s work.”

“This bill is under the guise of religious freedom for students, but it’s really designed to encourage students to pray and proselytize in public schools,” said Maggie Garrett, the vice-president of policy for Americans United for Separation of Church and State. “It adds more confusion than clarity, and of course current law already protects the rights of students,” she said.

The law’s predicted effects have divided critics and supporters. Opponents have said the bill will cause controversy-averse teachers and school administrators to hedge against correcting students who might cite religious beliefs in classwork.

Backers argue school officials are intimidated by “well funded groups” who are “biased against Ohio students’ religious freedom”. The most likely impact, groups such as the Anti-Defamation League said, is potential lawsuits against school districts.

Student religious liberty bills have spread across the US south and midwest for more than a decade with roots in a 1995 set of guidelines from the Clinton administration, according to a University of California, Davis law review article.

In 2007, Texas reincarnated the guidelines in a form which “intentionally lacks” some of the caveats the Clinton administration included, such as a prohibition on having a “captive audience” in school, the article said.

“This bill has been around since before the Project Blitz campaign, but the bill is part of the Project Blitz playbook,” said Garrett, the vice-president for Americans United for Separation of Church and State. “We will be seeing more of these bills in the future, because we’re certainly seeing an increase in other Project Blitz bills.”

In another example of their similarities, Project Blitz’s model legislation reads, “A student may organize prayer groups, religious clubs, and other religious gatherings before, during, and after the school day in the same manner and to the same extent that a student is permitted to organize secular activities and groups.”

Ohio’s bill said students could attend “religious gatherings, including but not limited to prayer groups, religious clubs, ‘see you at the pole’ gatherings, or other religious gatherings” and “may engage in religious expression before, during, and after school hours in the same manner and to the same extent that a student is permitted to engage in secular activities or expression before, during, and after school hours.”

Even though backers deny the bill has been designed to promote Christian values, others disagree. “It is negligent and reckless of our colleagues to push an agenda this way and act as if it is not based on this one religious tenet,” said Emilia Strong Sykes, the Democratic Ohio house minority leader and a Christian. “It is anti-American,” she said.

Long-term Republican control of Ohio state politics through gerrymandering – a process of drawing district lines to benefit one party – has turned Ohio into a proving ground for conservative legislation. Including 2019, Republicans have held all three levers of Ohio state government for 21 of the last 27 years, according to Ballotpedia.

Ohio was the first of several states to pass a six-week ban on abortion last summer. The same legislators introduced a bill to ban abortion outright last week, including new criminal penalties for “abortion murder”. Courts stopped Ohio’s six-week ban from going into effect. Abortion is legal in all 50 US states.

“My personal feeling, quite frankly, is this is disgraceful,” said Paul Beck, an Ohio State University political science professor and an expert on gerrymandering, about the Student Religious Liberties Act. “One of the products of gerrymandering and Republican domination we have in the Ohio general assembly is these are not necessarily reasonable people making our laws,” he said.

“Here you have legislation that is not only not needed, but will – at minimum – cause confusion,” said Gary Daniels, chief lobbyist for the American Civil Liberties Union of Ohio. The ACLU often sues on behalf of those who suffer religious discrimination, and opposes the bill.

Project Blitz is organized by the Congressional Prayer Caucus, the National Legal Foundation and the WallBuilders ProFamily Legislators Conference. Other Blitz proposals include proclamations to establish, “Christian heritage week” and a “public policy resolution favoring sexual intercourse only between a married man and woman”.

The privately run Congressional Prayer Caucus works to “preserve America’s Judeo-Christian heritage and promote prayer”, according to its website. WallBuilders is led by a widely criticized revisionist historian who claims the US was founded on Christian ideals. The not-for-profit National Legal Foundation aims to “create and implement” public policy “to support and facilitate God’s purpose for [America] … in such a way as to glorify the Lord Jesus Christ”.

When contacted by the Guardian, Steven W Fitschen, president of the National Legal Foundation, said “We are, of course, delighted that legislators in Ohio drafted a bill so similar to our model bill since we believe its provisions are constitutional and beneficial to students of faith in Ohio, without impinging on anyone else’s rights.”

Representative Timothy Ginter, the bill’s sponsor and a pastor, said he had “no knowledge” of Project Blitz. He declined further requests for an interview.

The Guardian contacted 11 co-sponsors of the legislation. None responded. The Guardian also contacted the legislator who originally introduced the legislation in 2016, former representative Bill Hayes. He did not respond to a request for comment.

In a statement, Ginter argued the bill is necessary, “Because of increased pressure on our schools from groups who are biased against Ohio students’ religious freedoms, many school officials are confused, and frankly intimidated by the threat of litigation from these well-funded groups.” He also denied the bill is meant to promote Christianity. “Nowhere in the language of the bill is a specific religion mentioned,” Ginter said.

The Republican-backed Ohio house passed the bill last week with a party-line vote. Only two Democrats voted in favor. The bill must be passed by the Republican-controlled Senate and the Republican governor, Mike DeWine, to become law. He did not respond to a Guardian request for comment.