ATHENS — A Greek trial for two dozen aid workers, some of them foreigners, is set to open on Thursday, charging them with espionage over their role in helping migrants who arrived in the country between 2016 and 2018.
The case will be heard in a court on Lesbos, the Greek island that was at the forefront of the European migration crisis that began in 2015.
The trial is opening at a time when Greece’s conservative government is toughening its stance on migration and on groups working with migrants, aligning itself with a hardening climate in Europe, which is grappling with a new migrant crisis at the Poland-Belarus border.
The Greek government has said it will not allow a repeat of the 2015-2016 crisis which saw thousands of migrants streaming across the Aegean Sea daily, overwhelming Greece’s rescue services. Rattled by fears of a new wave of refugees from Afghanistan, Greece has tightened the policing of its borders.
The defendants include 17 foreign nationals, some of them well-known activists such as Syrian refugee Sarah Mardini, the sister of the Olympic swimmer Yusra Mardini. The siblings captured international attention in 2015, at the peak of the migration crisis, after dragging their refugee boat to safety.
Ms. Mardini and the 23 other aid workers on trial could face up to eight years in prison if found guilty on charges of espionage, forgery and the unlawful use of radio frequencies. A police investigation alleged that they monitored Greek Coast Guard radio channels and used a vehicle with fake military license plates to enter restricted access areas on Lesbos.
The defendants are still under investigation over a number of suspected felonies, including human smuggling and money laundering, which could carry 20-year prison terms.
Their lawyers say all of the charges are trumped up.
“From the case file material and an investigation that lasted more than three years, essentially keeping the defendants hostage, not one piece of incriminating evidence has emerged,” said lawyer Clio Papantoleon, who represents some of the defendants.
Ms. Mardini, 26, could not travel to Greece from Germany, where she was granted asylum, to defend herself. She has been barred from entering the country since her release in December 2018 from a high-security prison in the capital, Athens, where she was detained for three-and-a-half months.
Sean Binder, a 27-year-old German-born Irish national who was arrested on the same day as Ms. Mardini in 2018, is expected to appear in court on Thursday. He was also detained for three-and-a-half months, on the island of Chios, before being released pending his trial.
“The idea that we’re spies is preposterous,” he said by telephone on Wednesday.
Mr. Binder said he had cooperated with the authorities, even calling the coast guard after spotting a migrant-smuggling vessel.
“In an ideal world, there would be no need for civil search and rescue,” he said. “But in the real world, there’s a gap, and it’s a gap into which people fall and drown.”
Human rights groups say the prosecutions are absurd.
“The charges they face are farcical and should never have come to trial,” Nils Muiznieks, director of Amnesty International’s European Regional Office, said in a statement on Monday. “Sarah and Sean did lifesaving humanitarian work, spotting boats in distress off Greek shores and providing those onboard with blankets, water and a warm welcome.”
Migration experts say the trial on Lesbos is emblematic of a broader shift toward the criminalization of refugees and aid groups.
“State authorities are progressively emboldened to take constantly harsher measures against migrants and those who help migrants,” said François Crépeau, an expert on international law and a former top United Nations official on the rights of migrants. Both official language and policies “increasingly portray migrants and their supporters as criminals.”
Mr. Muiznek, of Amnesty International, said criminalizing the activities of humanitarian groups was not only unfair but counterproductive.
“Stopping rescue operations doesn’t stop people from making dangerous journeys,” he said. “It simply makes those journeys more perilous.”
The case against the workers has been described in a European Parliament report as “currently the largest case of criminalization of solidarity in Europe.”
The Greek migration and justice ministries said they could not comment as the case is in the courts and they have to respect the independence of the judiciary.
But this is not the first time aid workers have found themselves in Greek courts. A similar trial on Lesbos in 2018 — of Spanish and Danish workers — led to the rescuers’ acquittal.
And more trials are likely to come.
More than 40 rescue workers face prosecution on charges including violating state secrets laws, according to two case files prepared by the Greek police over the past year-and-a-half.
Aid workers have also been prosecuted in other European Union countries such as Italy, which faced a new migrant influx this year.