The study, by Howard Reed, an economist, predicts that the number of children with at least four “indicators” of vulnerability – such as poor housing, unemployed parents, or disability in the family – will jump from 885,000 to more than a million by the end of the current Parliament.
The number of children at the extreme end is set to more than double to 100,000 in that time.
It estimates that changes to housing benefits and public services cuts will leave the poorest households £3,000 a year worse off.
Matthew Reed, chief executive of the Children’s Society, said: “That means three children in every class in the UK will be living in a situation where parents are making choices [such as] is it going to be breakfast or is it going to be dinner; three children in every class where parents are going to be saying is it going to be heating the house properly or is it going to be proper shoes to wear to school.
"That is an outrageous situation to be in in our society today … that is a scandal, it is a moral outrage.”
Andrew Flanagan, chief executive of the NSPCC, added that rhetoric about parents’ benefit dependency should not be allowed to harm children’s futures.
He said: “It is always the case that the kind of comments people make start from the perspective of adults: [that] it is the adults who have been feckless, it’s the adults who have been irresponsible.
“But actually our responsibility is not towards adults, our responsibility is towards children.”
It follows a poll by the parenting website Netmums wich found that one in four parents know of a child in their area they think might be going hungry.
Siobhan Freegard, founder of Netmums, told how she had seen children queuing to be fed through a project run by the charity Kids Company.
“What frightens me so much is that there is a queue there of an hour a day, little children with a plastic bowl queuing up for food.
“And Kids Company have to go out and raise money to feed those children who are turning up themselves, so the system somewhere is fundamentally broken down.”