Some of England's most vulnerable children may lose out under planned changes to the child protection system, a new campaign group has argued.
The government wants to cut bureaucracy and replace more than 700 pages of guidance with three short documents.
But the group Every Child In Need say the new rules are too vague and risk letting local authorities "do what they want when they want".
Organiser Steve Broach said the changes risked harming vulnerable children.
Mr Broach, a specialist children's rights barrister, told BBC News: "In a time of cuts to take away minimum standards to vulnerable children and to rely on individual local authorities to get it right every time on their own is dangerous and irresponsible."
The group is particularly concerned that the relaxing of the rules may lead to delays.
For example, the government proposes removing the requirement for local authorities to prepare an initial assessment of a child's needs within seven working days of a referral and a more detailed assessment within seven weeks.
Referrals can be from lawyers, schools, neighbours, the police or anyone else who raises concerns about a child's welfare or well-being.
The group fears that "many local authorities - cash-strapped following swingeing cuts to their budgets - are happy to take this lifeline which will mean less pressure to act quickly when a child in need comes to their attention".
It argues that, far from cutting bureaucracy, the changes will remove "an essential safety net for children when they are failed by their local authority".
The group also says the new rules are overly-focused on child protection and will ignore a much larger number of children who have significant needs but are not at immediate risk of abuse.
They give the examples of disabled children, homeless children or children who have been trafficked.
Mr Broach, of Doughty Street Chambers, said: "To focus solely on children who are already at risk of significant harm and ignore those with lower-level needs is going to result in an explosion of child protection cases down the line."
Campaign supporters, the National Deaf Children's Society, said it was concerned the changes would "make it harder for deaf children in England to get the social care support they need".
"These changes threaten to weaken vital protections and make a bad situation worse," it added.
The government's proposals follow a review last year which said social workers should be freed from bureaucracy.
In the wake of the death of Baby Peter in Haringey, north London, Education Secretary Michael Gove asked social policy expert Professor Eileen Munro to assess the child protection system in England.
Ministers have responded by announcing that three guidance documents, totalling 68 pages, will replace more than 700 pages of current guidance.
The new structure is currently being piloted by eight local authorities.
A Department for Education spokesman said: "There is nothing more important than protecting the welfare of vulnerable children, and this is precisely why we have cut burdensome red tape to let professionals get on with their jobs.
"Professor Munro's review of child protection recommended that we reduce unnecessary bureaucracy to free up professionals to give to right help to all vulnerable young people.
"We agree and that's why we are making these changes."
In July, a progress review for the government by the Childhood Wellbeing Research Centre found that social workers welcomed the new system and were able to do more family visits.
Critics have complained the researchers did not speak to any children or families involved.