Proposals to make sex and relationships education compulsory in schools were defeated in the House of Commons on Tuesday.
An amendment to the Children and Families Bill was tabled by Labour and could have resulted in compulsory gay marriage lessons in schools.
It also would have scrapped the right of parents to remove their children from sex education lessons. But MPs voted 303 to 219 against the clause.
Education Minister Edward Timpson said in the debate the Government felt it was unnecessary to change the law.
He said: “The Government do not believe that the right of parents to withdraw their children from sex and relationship education should be diminished in the way proposed.
“We see no need to amend the existing legislation, which provides a clear and workable model for schools and parents.”
Mr Timpson also said they “strongly believe” teachers need to be able to use their judgement to decide when and how best to provide sex and relationship education in their classrooms.
Tory MP Fiona Bruce said in the House of Commons that parents should be involved in talking to their children about sex, and warned that this amendment would actually distance rather than involve them.
She said: “I cannot agree that that is the right approach at a time when many people are concerned that we live in a society in which opportunities for parental involvement and influence need strengthening and encouraging, not reducing and diminishing.”
She added: “Throughout this afternoon’s debate, I have repeatedly heard Ministers and others say how important it is to take into account parents’ views with regard to other aspects of education. Surely that should apply in this critical area of a child’s education.”
But another Conservative MP Sarah Wollaston, a former GP, said she supported a change in the law.