Opponents of plans to appoint a “named person” for every child in Scotland will hold a rally in Perth.
The contentious measure, which assigns a single point of contact, such as a teacher or health visitor, to look out for under-18s, is already being piloted.
But the No To Named Persons (NO2NP) coalition claimed the policy breaches data protection and human rights laws.
Campaigners say Tuesday night’s meeting in Perth will apply extra pressure ahead of an appeal hearing against at the Supreme Court in London.
Tory MSP for Mid-Scotland and Fife Liz Smith will be among the main speakers at the gathering in the city’s Salutation Hotel.
She said: “It is very clear that the named person policy is not only deeply unpopular with the vast majority of parents across Scotland, but it is also unnecessary and will take vital resources away from the most vulnerable children who need the most help.
“The key issue for most families is the fact that it undermines trust in the family unit and implies that the state rather than the parents know best how to raise children.
“This is clearly unacceptable.”
The NO2NP campaign is taking its fight to the Supreme Court after losing a legal battle at the Court of Session in Edinburgh.
Judges dismissed the group’s arguments as “hyperbole”.
The Scottish Government said the policy would act as a safety net to help families and children if they need it, to speed things up and avoid families having to speak to numerous different services.
The NO2NP is an umbrella organisation led by the Christian Institute and backed by the charity Christian Action Research and Education (Care) and the Family Education Trust.
A spokesman said the move will “undermine parental authority” and “allow state officials unprecedented powers to interfere with family life”.
He added: “These meetings will give ordinary mums and dads the opportunity to come along and hear the real risks this ‘Big Brother’ legislation poses to family life and let them know why so many people are saying No To Named Person.”
The open Perth meeting will be held at the city’s Salutation Hotel, South Street, from 7.30pm.