Denis Naughten says 1,500 children registered as attending primary school never make it to secondary education.

While part of the figure may be due to emigration, Mr Naughten — now anindependent TD after being thrown out of the Fine Gael parliamentary party for opposing health cuts — believes the rest of the so-called children are invented as part of a benefits scam.

Mr Naughten wants the education and social welfare departments to integrate their computer systems in order to deal with the problem.

The outspoken TD has also called for child benefit to be replaced with a school attendance allowance.

More than €1.9bn in child benefit is paid to 606,000 families in respect of some 1.15m children, and Mr Naughten says up to €135m of that is being scammed or incorrectly assigned.

“Almost 1,500 children leave primary school and are not recorded as turning up in secondary school,” he said.

“We have a severe problem that is building serious social issues for the future.

“The figures used to be about 1,000 and have not increased. Part of this may be due to emigration, but there is also a large-scale benefits scam going on here.

“I think abolishing child benefit for school- age children and its replacement with a school attendance payment would solve the problem.

“This would take account of children who are ill or home-schooled, and would be paid in the same manner and at the same rate as child benefit.

“Not only would this keep children in school; it would also save the exchequer between €100m and €135m annually.

“The administration system is already in place and the education department and social welfare should harmonise their computer systems.

“The control division of the Department of Social Protection brings in savings of between €75m and €85m under the child benefit scheme.

“And another €5m is sought from overpayments annually. Introducing such a payment system would also have a significant impact on child benefit fraud and over-claims, saving the taxpayer €10.5m to €36m,” the TD said.

Frances Fitzgerald, the children’s minister, said there was no evidence that switching to a school attendance allowance would combat truancy.

The Government also insists that EU law on benefits prevents it from making such a change.