Church leaders are making a last-minute appeal to MPs to protect teachers who believe marriage should only be between opposite sexes even if Louisa Wall's gay marriage bill is passed tomorrow.
National leaders of the Catholic, Presbyterian, Baptist and several Pentecostal churches issued an open letter yesterday asking MPs to vote down the bill.
Failing that, they want them at least to amend it to prevent discrimination against any teacher or other person who believes that marriage should only be between a man and a woman.
Christian Network director Glyn Carpenter said it was still possible for the bill to be defeated when it comes up for a second reading about 8pm tomorrow. But, after a vote of 80-40 at its first reading last August, he urged MPs to at least amend it.
He proposed an amendment that "any person or organisation shall retain the right to hold the belief (on cultural, religious or other grounds) that marriage should only be between opposite sexes, and persons and organisations holding or respectfully expressing such a belief may not be discriminated against in any way".
"People should not be denied employment, they should not be denied promotion, and should not be dismissed from employment for refusing to go along with the new definition of marriage," he said.
Some teachers worried they could face accusations of discrimination if they did not teach that all marriages were equal.
The Rev Stuart Lange of the Presbyterian Affirm movement said the change was needed to stop the Government from fixing funding criteria that discriminated against religious-based social service agencies that did not support gay marriage.
However, the two men said they did not yet have an MP willing to move such an amendment.