Nationals backbencher George Christensen, a strident critic of the Safe Schools Coalition program, expects a majority of his backbench colleagues to sign a letter he is drafting on Wednesday.

The MPs are not happy with an independent review of the program, which Christensen said operated under a tight terms of reference drafted by Education Minister Simon Birmingham.

They were briefed on the findings of the review on Tuesday night, but left the confidential meeting unimpressed.

“Nothing that was advised to me has changed my opinion, it’s probably strengthened the concerns I have about it,” Christensen told ABC radio, citing program materials, some of the online links children are being directed to and what they were being taught about sexual and gender diversity issues.

“It’s really moved beyond an anti-bullying program to something else.”

Christensen says “gravely concerned” parents and teachers should be allowed to air their concerns to a parliamentary inquiry into the program.

Former cabinet minister Eric Abetz said the review had not changed his mind about the program.

“It has more to do with pushing an agenda and not anything to do with genuine anti-bullying programs,” he told reporters.

Cabinet minister Mitch Fifield said everyone in parliament was at one on not wanting to see children bullied.

“Colleagues were very happy that Simon Birmingham initiated the review, we’ll see what the result is and then we’ll make a decision,” he told ABC radio.

Labor leader Bill Shorten accused the MPs of being a “tin foil hat brigade” who wanted to second guess school councils and principals.

He called on Prime Minister Malcolm Turnbull to show some leadership and back the education minister over the “lunar right” of his government.

Greens senator Robert Simms urged coalition MPs to drop their attack on the program and move on.

“This review was pointless to begin with and now we’ve got coalition MPs throwing a tantrum because they don’t like the outcome,” he said.

AAP