Lack of funding could threaten child protection reforms which were called for in the wake of the Victoria Climbie tragedy, MPs have warned.
The Every Child Matters scheme was set up after Victoria's death
The Commons Education and Skills Select Committee welcomed the "ambitious and comprehensive" Every Child Matters scheme but doubted funds were in place.
The government says it is making more resources available.
A report into Victoria's murder in London in 2000 found she had been let down by failings at several agencies.
Victoria was murdered by her great-aunt Marie Therese Kouao and partner Carl Manning in Tottenham, who are both in prison serving life sentences.
Lord Laming's 2003 report into her death concluded that she had been let down by failings and bureaucracy in several agencies.
Under the Every Child Matters scheme, set up after the inquiry, a computer data system will contain information on all children.
The programme intends to ensure that children achieve five main outcomes: to be healthy; to stay safe; to enjoy and achieve; to make a positive contribution; and to achieve economic wellbeing.
There are also plans for local authority-led Children's Trusts, which would co-ordinate key agencies involved in child protection.
But chair of the cross-party committee, Labour MP Barry Sheerman, says the government expects improvements to services to be largely resourced from mainstream budgets and savings.
He said witnesses have said this will be difficult to achieve in practice.
The committee highlighted the following:
Whether there will be enough money for training of in-service staff
Whether IT-based child indexes will be the best use of resources
Potential security concerns of such indexes
The fact that schools and GPs have not been placed under a direct "duty to co-operate" in partnership arrangements.
"There is a real risk that a minority of schools and GPs could choose not to participate," Mr Sheerman added.
A Department for Education and Skills spokesman defended the scheme, saying: "Our trailblazers, which are piloting information sharing, are working well and will provide useful evidence."
"We have devoted substantial resources to children's services, including £4.5bn in children's social services.
"The government is making additional resources available... including specific resources for development of the children's workforce of £15m in 2006-07 and £30m in 2007-08," the spokesman added.
The spokesman also said plans for a nationwide child protection database would not be implemented until the system is "technically robust".