The first group of unaccompanied children without links to Britain arrived in the UK last night from the Calais camp known as the “jungle”.

The refugees were among the latest wave of around 70 new young arrivals to cross the Channel under the provisions of the Dubs amendment.

It followed a change to the Immigration Act which meant Britain has to accept some of the “most vulnerable” unaccompanied child refugees who do not necessarily have ties to the UK.

Previously all the young refugees who have arrived in Britain have been brought under the Dublin regulations, which require the children to have family resident in the UK.

Speaking about the new arrivals, Bishop Jonathan Clark, spokesman for Citizens UK, said: “It’s great to see government acting on what Citizens UK have been calling for and transferring these children to Britain.”

But he added: “Of course this is just a very small proportion of the unaccompanied children out there and less than 1% of the total number of people in the Calais camp now, the vast majority of whom will be claiming asylum in France as they should.”

Some of the first wave of arrivals earlier week provoked speculation over their ages amid suggestions some appeared to look much older than teenagers.

The Sunday Telegraph reports that the Home Office rejected an offer of expert help to establish the ages of refugees seeking to come to the UK from the “jungle”.

It said specialist social workers were offered to the Home Office in August but the Local Government Association said officials did not take up the offer and only started asking for specialist help on Friday.

A Home Office source insisted the support had not been needed when it was offered in August.

Demolition teams are preparing to move into the “jungle” on Monday to clear the estimated 6,500 inhabitants who will be relocated to reception centres across France.

British members of anti-capitalist protest group No Borders are heading to Calais in an attempt to block the demolition of the camp, The Sunday Times said.

At a meeting in south-east London last Sunday, one activist told the paper that “lots of us will be going down” and warned people should not join them unless they “understood the risks”.