A bipartisan bill that would stop convicted sex offenders from working in schools has been passed by the House but is running into a foe as it heads to the Senate: major teachers' unions like the National Education Association and the American Federation of Teachers.

Kyle Olson, with the Education Action Group Foundation told Megyn Kelly Wednesday night on “The Kelly File” that the unions’ objection to the bill proves “unions are out to protect the adults…they are not out for the interests of the children.”

“We should have zero tolerance for issues like this,” Olson said. “We have zero tolerance policies for weapons, a kid who bites a Pop Tart into a gun or has a Hello Kitty bubble-maker will be suspended or expelled if they have those sorts of things…”

The measure would require school systems to check state and federal criminal records for employees with unsupervised access to elementary and secondary school students, and for people seeking those jobs. Workers refusing to submit to the checks would not be allowed to have school positions.

In letters to lawmakers, the unions have claimed the measure might jeopardize workers' protections under union contracts.

Additionally, Rep. Keith Ellison, D-Minn., has spoken out against the bill, saying it does not allow for people to overcome their criminal backgrounds.

Olson said that the bill is not attempting to stop sex offenders from working altogether, but “they shouldn’t be in a school.”

“They shouldn’t have direct access to children,” Olson said. “Again, I think that is a no-brainer.”

The Associated Press contributed to this report