I have an expert opinion entitled No State of Exception at the EU External Borders in the first place.
It states that EU states may not suspend the right of asylum or refuse to accept asylum applications. Greece has acted illegally by suspending the right of asylum for one month. Pushbacks or deportations without an individual procedure violate EU and international law. Pushbacks or deportations without an individual procedure cannot be justified under EU law or European human rights law. Dealing with people on the Turkish-Greek EU external border violates the fundamental values of the Union such as the rule of law and respect for human rights.
You can find the full report under this Link