It has proved the most controversial aspect of the original guidelines agreed by the National Forum for Values in Education and the Community, the 150-strong group set up by the School Curriculum and Assessment Authority to determine which values were universal and should be taught in lessons.

A small, but vociferous five-strong minority was upset that original guidelines, published in October, said families were valued as sources of love and support but did not mention marriage.

Gillian Shephard, the Education Secretary, also said that she wanted more emphasis on the family. The new version of the statement, drawn up after a widespread MORI consultation, is clearly a compromise in that it falls short of wholehearted support for marriage.

Those among the 3,200 schools, 1,455 adults and 400 organisations polled by MORI who wanted greater emphasis on families and marriage were almost evenly matched by those who did not.

Moreover, the forum has made it clear that it does not want to devalue the experience of children growing up in non-traditional families.

Accordingly, the new version of the statement on families reads: “We value truth, human rights, justice and collective effort for the common good.

“In particular, we value families as sources of love and support for all their members, and as the basis of a society in which people care for others.

“On the basis of these values, as a society we should support marriage as the traditional form of family while recognising that the love and commitment required for a secure and happy childhood can be found in families of other kinds.”

Guy Hordern, one of the Forum’s five dissidents, said the move was insignificant and marriage should be described as the ideal.

The changes suggested will be discussed at the next meeting of SCAA in January.