Republican Texas State Senator Donna Campbell on Monday proposed an amendment to the Texas Constitution which could allow business owners to refuse to hire and/or serve gays based on a “sincerely held religious belief.”

Campbell's Joint Resolution 10 would go beyond the state's current Religious Freedom Restoration Act (RFRA), which prohibits the government from placing a “substantial burden” on an individual's religious freedom. Campbell's proposal removes the “substantial” requirement and exceptions for enforcement of civil rights laws, according to Lone Star Q.

Campbell unsuccessfully championed a similar measure two years ago.

Critics of Campbell's original proposal argued that it could be used by business owners to claim a religious exception to nondiscrimination ordinances, including Houston's recently enacted gay-inclusive measure strongly opposed by Christian conservatives.

To take effect, the proposal requires the approval of lawmakers and voters.