Education Secretary Michael Gove has thrown his support behind the proposed legalisation of same-sex marriage and promised teachers would not be disciplined for refusing to promote it.
Concerns have been raised ahead of a Commons vote on Tuesday to legalise gay marriage that thousands of teachers could face the sack because they object to the new law.
But Mr Gove made clear that while teachers would have to explain that it is legal, they would not be required to actively promote it.
Writing in today's Mail on Sunday, Mr Gove explained his stance, saying it was wrong to say to gay men and women that their love is less legitimate.
He said: "It's wrong to say that because of how you love and who you love, you are not entitled to the same rights as others. It's wrong because inequality is wrong."
He continued: "Marriage is not undermined by extending it to gay people - it is reinforced by including everyone equally."
Offering reassurance to teachers who might oppose the proposals, he said: "Some teachers are concerned that equal marriage legislation may require them to teach views which go against their beliefs and open them to threats - either in the workplace or the courts - from those who hold diverging views.
"I want to reassure those teachers today because so many of our best, and wisest, teachers are people of deep religious faith.
"Some of the schools I most admire are faith schools and their success is inextricably bound up with their religious ethos.
"If I thought any legislation, however well-intentioned, would make life more difficult for great teachers and great schools I wouldn't support it.
"I have complete confidence in the protection our law offers freedom of conscience and speech.
"There is a significant difference between expecting a teacher to explain something and requiring them to promote it.
"Teachers are expected to explain the world as it is in a way which is appropriate to the age, stage and level of understanding of pupils.
"This includes explaining some things of which they do not necessarily approve, such as divorce and abortion.
"The same will apply to new forms of marriage. Teachers will not be able to pretend that legal marriages between same-sex couples do not exist, but there will be no requirement to promote them.
"That position will not be changed by the new definition of marriage."