Armed forces children are losing “large parts” of their education and the Government still has no idea how many there are in the system, despite being told the situation was “unacceptable” in 2006, the education watchdog said today.

Ofsted reveals that pupils already suffering “anxiety and stress” because of their parents’ jobs and frequent moves, are missing or repeating substantial sections of the curriculum as schools fail to transfer records.

The report comes in the week that ministers pledged to legally enshrine a military covenant that includes a provision that armed forces children should have the same standard of, and access to, education as any other UK citizen.

But Ofsted reports that schools have a “general lack of awareness of service families and their additional needs”. It estimates the pupils make up one in 200 of the overall total in England, but says there is still no definitive Government figure.

Chief schools inspector Christine Gilbert said: “There is more we should be doing. Information about each child’s standards, progress and needs should be passed effectively from school to school in order to ensure their learning and development is as good as possible.

“Too often this is not done well enough and many service children are missing large parts of their curriculum and essential training in key areas and they struggle to catch up. This is made all the harder given their anxieties about their parents when on active service.”

The Commons defence select committee called for closer co-operation between government departments to support forces children five years ago, declaring it “unacceptable” that they did not know how many were in education.

Today Ofsted says that remains the case although the Department for Education now collects numbers from state schools in England.

But that does not include pupils in independent schools or those on overseas bases. The Ministry of Defence (MoD) does not require service personnel to declare children on their records and overall estimates vary between 38,000 and 175,000.

Ofsted is calling on the MoD to maintain an accurate register. The watchdog also highlights problems with school admissions that mean that some service families are forced to send siblings in the same key stage to different schools.

It recommends that local authorities re-evaluate admissions procedures to ensure they “take appropriate account of requests from service families for school places”.

Ofsted reports that continual moves have a “considerable impact” on armed forces pupils’ social and emotional development.

They were exacerbated by the unco-ordinated transfer of records between schools which meant “important information was delayed or did not arrive at all”.

There were particular difficulties in transferring records of statements of special educational need (SEN) and general slow assessment and support for service children with SEN or a disability.

An MoD spokesman said the Government was providing a pound;200-per-pupil premium for services children to help provide pastoral assistance for them and a pound;3m fund would help schools with high numbers of service children.

On recording pupil numbers, he said: “Parents cannot be compelled to record their children as service children, and some prefer not to for fear of being treated differently. We have noted all of the findings of the report and will respond in due course.”

175,000 - Number of forces children, according to some estimates.