Delays in the resettlement of migrant children forced out of the "Jungle" camp in Calais after its demolition are leaving some at risk of suicide, a charity has warned.

Citizens UK said the pause in transfers of children claiming a legal right to live in Britain from France during the last week has left many suffering a "significant deterioration" in their mental health.

It said 15% of those in Calais at the time of the camp's demolition had arrived, with some 1,600 young migrants and refugees transferred by bus to 60 centres across France.

Some 300 unaccompanied children have been brought to Britain and the Government is committed to transferring hundreds more, the Home Office said.

Citizens UK said of 40 children they are supporting in France, one third have expressed suicidal thoughts and lack of care of their own life since the demolition, 75% have showed an alarming deterioration in mental health and 90% have reported increased anxiety.

Dr Susannah Fairweather, a consultant psychiatrist who has worked as an independent medical witness assessing unaccompanied minors in Calais, said further delays were creating a "cumulative trauma" which would make settlement more difficult once they do arrive in the UK.

And she said the country was not prepared enough to deal with the "complex" issues that many experience.

Dr Fairweather added: "The delay can cause significant deterioration in the children's mental health, including the stark risk of suicide."

She continued she did not believe the UK was prepared for all the different needs of child migrants, and that a multi-agency approach was required, adding: "Certainly I don't think there's direction."

Citizens UK staged a small demonstration outside the Home Office's Lunar House in Croydon on Sunday afternoon to urge that the transfers resume immediately.

Citizens UK demonstrators outside the Home Office. Credit: PA

Volunteers and faith leaders held up banners and posters reading "refugees welcome" and "restart the rescue".

Rabbi Janet Darley, who was among the handful of supporters, said: "We are not responsible for every single child but we should take our fair share."

A Home Office spokeswoman said: "We are working closely with the French government and other partners to identify unaccompanied asylum-seeking children who are eligible to come to Britain.

"Our focus is, and will continue to be, transferring all eligible minors to the UK as soon as possible and ensuring they arrive safely."

Children's eligibility under the Dublin regulation or Dubs amendment would be considered at the temporary centres in France and transfers would resume in the "coming days and weeks", she added.