Refugees and migrants who cross by boat from Turkey to Greece’s Aegean islands must be allowed to travel on to the mainland, a Greek court has ruled, raising concerns about a fresh wave of asylum seekers to Europe.

The ruling comes two years after border closures and a controversial deal with Turkey shut down the Balkan migration route.

It could act as an incentive for refugees, including Syrians fleeing recent attacks by regime forces, to head for Greece with the aim of reaching northern Europe.

The decision was met with fury, however, by the 15,000 asylum seekers who have been stuck in camps on the islands for up to two years. The ruling does not apply retrospectively and so they will not be allowed to leave until their applications have been considered - a tortuously long process. Under the new ruling new arrivals may be able to effectively jump the queue and go straight to the mainland.

Protests and riots have broken out in the camps in the past and container cabins and other structures have been set on fire amid rising tensions with authorities.