But the cities can only make good on their pledge if national governments agree. Seven of the 10 local government signatories to the letter are in countries that have not volunteered to take in children under a relocation effort launched by the European commission in March.

Rutger Groot Wassink, Amsterdam’s deputy mayor for social affairs, said it was disappointing the Dutch government had declined to join the EU relocation scheme. He believes Dutch cities could house 500 children, with “30-35, maybe 40 children” being brought to Amsterdam

“It’s not that we can send a plane in and pick them up, because you need the permission of the national government. But we feel we are putting pressure on our national government, which has been reluctant to move on this issue,” he said.

The Dutch government – a four-party liberal-centre-right coalition – has so far declined to join the EU relocation effort, despite requests by Groot Wassink, who is a member of the Green party.

“It might have something to do with the political situation in the Netherlands, where there is a huge debate on refugees and migrants and the national government doesn’t want to be seen as refugee-friendly. From the perspective of some of the parties they feel that they do enough. They say they are helping Greece and of course there is help for Greece.”

If the Dutch government lifted its opposition, Groot Wassink said transfers could happen fairly quickly, despite coronavirus restrictions. “If there is a will it can be done even pretty soon,” he said.

Ten EU countries – Belgium, Bulgaria, France, Croatia, Finland, Germany, Ireland, Portugal, Luxembourg and Lithuania – have pledged to take in at least 1,600 lone children from the Greek islands, just under a third of the 5,500 unaccompanied minors estimated to be in Greece.

So far, only a small number have been relocated: 12 to Luxembourg and 47 to Germany.

The municipal intervention chimes with comments from the German Social Democrat MEP Brigit Sippel, who said earlier this month that she knew of “cities and German Länder who are ready … tomorrow, to do more”. The MEP said Germany’s federal government was moving too slowly and described the initial transfer of 47 children as “ridiculous”.

Amsterdam, with Utrecht, organised the initiative through the Eurocities network, which brings together more than 140 of the continent’s largest municipalities, including 20 UK cities. The UK’s home secretary, Priti Patel, has refused calls to take in lone children from the Greek islands.

Groot Wassink said solidarity went beyond the EU’s borders. He said: “You [the UK] are still part of Europe.”