The charity says the legal aid bill, debated in parliament today, will affect the most vulnerable children and carry "grave consequences".
The government has stated that for some excluded cases there will be a safety net in the form of an exceptional funding scheme – but the Children’s Society say thousands of children will not be eligible for this scheme.
It wants the government to provide legal support for all children – a move, which, according to the government’s own calculations, would cost £10m a year.
In its current form, the bill would lead to cuts in areas of law including education, housing, immigration and clinical negligence.
Many children, including unaccompanied migrant children and victims of trafficking, will be left to navigate the legal system with no support. This could include going to court without a lawyer.
"We believe that different principles should apply to children in an adult legal system," said Children's Society chief executive Bob Reitemeier.
"All children should have access to good quality publicly funded legal advice and representation. Legal aid is already limited to those who can’t afford it.
"These changes will also affect the poorest and most marginalised families in our society and many more children will suffer as a knock-on effect. It is imperative that access to justice is maintained."
