Leaders from more than a dozen children's groups are uniting to back the provision but critics have pledged to create a constitutional crisis.
They are lobbying UK Coalition Government ministers and law officers, along with Holyrood's presiding officer, to strike down this aspect of the Children and Young People Bill on the grounds that it breaches the European Convention on Human Rights. A Scottish Government spokesman said: "We are confident that the Bill is compliant with the European Convention on Human Rights. Families are not required to accept advice or offers of help from the Named Person. Any actions or advice from the Named Person must be fair, proportionate and respect rights with the aim of safeguarding the wellbeing of the child."
The heads of 13 charities or groups representing children - including Children in Scotland, Children First and Barnardo's - have urged ministers to stick to their guns. They said: "We strongly support the principle of the Named Person, which essentially puts in legislation the practice of a more joined-up approach to children's services already being rolled out in most local authorities across Scotland under the Getting it Right for Every Child framework."
That framework was brought in by the Labour-LibDem administration under Jack McConnell but until now it has not been enshrined in law. This week's Bill also has sections on increased childcare and after-school support, adoption and the duties and powers of ministers and the Children's Commissioner.
The latest threat of a legal challenge has come from the Christian Institute, part of the Scotland for Marriage campaign group, and cited leading QC Aidan O'Neill as saying this breached European law as an "unjustified interference" into private and family life.
Christian Institute director Colin Hart said: "It is nothing less than a state-sponsored, fundamental attack on ordinary parents and their rights to raise their children."