Theresa May must intervene “as a matter of urgency” to speed up the transfer of child refugees from camps in northern France to Britain, Jeremy Corbyn has said.

The Labour leader wrote to the Prime Minister on Wednesday warning that is was still “worrying unclear” how the Government intended to stand by its commitment to help the unaccompanied minors.

Earlier this year the Government accepted the so-called Dubs Amendment and committed itself to taking in children in the camps.

Mr Corbyn however noted in a letter that despite the Home Secretary holding the papers for 212 children eligible under the Dubs Amendment “five months after the Dubs amendment to the Immigration Act, none of the qualifying children have been brought to the UK”.

“With the imminent closure of the Calais camp, it is imperative that the Office of the Prime Minister intervenes as a matter of urgency to ensure that this process is prioritised – and the many vulnerable children who have already been through the trauma of fleeing violence and destitution, and are now at risk of slavery and trafficking, are finally given refuge here in the UK,” he said.

In July Lord Dubs, himself a former child refugee to Britain who fled from the Nazis, warned that Britain was breaking its pledge to help the children. He said that now the EU referendum was out of the way the Government should begin the process.

Jeremy Corbyn, Labour leader (PA)

Mr Corbyn wrote: “I am writing to you to express my deep concerns about the obvious delay in implementing the Alf Dubs amendment and commitments to help child refugees.

Calais Refugee Children arrive in UK Show all 9 1 /9 Calais Refugee Children arrive in UK Calais Refugee Children arrive in UK A coach carrying the first group of unaccompanied minors from the Jungle migrant camp in Calais to be brought to Britain arrives at an immigration centre in Croydon, south London Reuters Calais Refugee Children arrive in UK A Catholic priest chats to Muslim Imans as they wait for the arrival of the coach carrying the first group of unaccompanied minors from the Jungle migrant camp in Calais to be brought to Britain arrives at an immigration centre in Croydon, south London Reuters Calais Refugee Children arrive in UK Fourteen migrant children from the 'Jungle Camp' in Calais are due to arrive in the UK today to be reunited with relatives Getty Calais Refugee Children arrive in UK Young men are escorted after stepping off a coach at the Home Offices Lunar House Getty Calais Refugee Children arrive in UK A boy is escorted after stepping off a coach at the Home Offices Lunar House after arriving from the Calais 'Jungle Camp' Getty Calais Refugee Children arrive in UK UK Border Force staff escort the first group of unaccompanied minors from the Jungle migrant camp in Calais to be brought to Britain as they arrive at an immigration centre in Croydon, south London Reuters Calais Refugee Children arrive in UK A young boy arrives on a coach at the Home Offices Lunar House after leaving the Calais 'Jungle Camp.' Fourteen migrant children from the 'Jungle Camp' in Calais are due to arrive in the UK today to be reunited with relatives Getty Calais Refugee Children arrive in UK British former Archbishop of Canterbury Rowan Williams, center, flanked by Bethany Gardiner-Smith, left, from the Citizens UK charity and Bishop of Croydon Jonathan Clark speaks to the media about the 14 migrant children who will be resettled in the UK, outside Croydon Minster church in Croydon, south London AP Calais Refugee Children arrive in UK Asif Khan whose brother Aimal Khan was one of fourteen migrant children who arrived in the UK, speaks to the media outside Lunar House in Croydon, south London. The 25-year-old chef has been living in the UK for 11 years, having fled Afghanistan himself. His brother Aimal Khan, 14, also from Afghanistan, had been stranded in the Jungle for six months PA

“The Dubs amendment instructed the Government to act decisively and quickly to give security and sanctuary to child refugees who are alone and at high risk of abuse in the continent of Europe.

“The Government has also pledged to speed up the process for lone child refugees who are, under the Dublin agreement, entitled to join family here in the UK.”

This week tabloid newspapers and Conservative MPs made unsubstantiated claims that children being brought to the UK were in fact adults, based on what they judged to be the children’s mature appearance.

Joined by former New Labour minister Jack Straw they called for dental checks to determine the age of the children, though no such accurate checks to determine age in fact exist.