Hundreds of child asylum seekers in France expecting to come to the UK have had their Home Office claims rejected, it has been reported.

Children who were dispersed from the Calais refugee camp in October were advised to lodge their asylum applications from France. However, it has been confirmed only a fraction have been accepted.

According to Home Office figures, of the 1,900 children who were registered with aid agencies after the demolition of the camp, only 750 have been brought to the UK.

Toufique Hossain, the director of public law at the UK-based Duncan Lewis solicitors, who is representing a large number of asylum seeker children told the Guardian he had been in touch with several of the children since their claims were rejected.

"From the reports we have received it seems as if this is an organised operation between the Home Office and the French authorities," he said.

"The children have been told verbally that their asylum claims have not succeeded, but they have not been given any reasons why in writing. This is absolutely shocking."

One of the children to be denied asylum was 15-year-old Taher from Eritrea, who said he was devastated by the news.

He said: "I have been on hunger strike since Sunday, drinking only water and coffee to protest about the unfairness of the Home Office keeping us waiting for so long.

"We haven't been able to go to school or anything while we have been waiting. And now we have heard this very bad news."

Taher told the Guardian he and many of the boys were planning on running away, rather than lodge their asylum claims with France, having becoming distrustful of the authorities there.

"Some will try to get to the UK on a lorry from Belgium. I think I will go back to Calais and try to get to England that way," he said.

Hossain said he would challenge the Home Office's decision, after they confirmed the current phase of transfers were concluded.

He said: "These children are very vulnerable. They have just been told verbally that they can't come to England without an appropriate adult present to help them deal with this news.

"We are now looking to see what we can do legally to challenge the fact that the Home Office have failed to provide us with written reasons why they have rejected the children's asylum claims."

A Home Office spokeswoman said: "We have been working with the French authorities to bring children eligible to come here and more than 750 children have arrived so far. We are working closely with the French authorities to ensure the remaining children in their care are provided with information on how to claim asylum in France.

"The current phase of transfers is being concluded. This is a planned process, done in conjunction with the French authorities. We have interviewed all the children who were transferred from the camp to the children centres in France. Those transferred to the UK include all Dublin cases where the family relationship has been verified."