ISTANBUL - Thirty-five supporters of Turkish top-flight football side Besiktas went on trial Tuesday in a hugely controversial case on charges of seeking to overthrow the authorities led by President Recep Tayyip Erdogan in 2013 protests.

Hundreds of Besiktas supporters surrounded the Istanbul criminal court as the trial opened, shouting football chants backing the accused who are all members of the club’s main fan club, the Carsi Group.

Prosecutors have accused all 35 suspects of seeking to stage a coup to overthrow the government of Erdogan, who was then prime minister, during the unprecedented protests against his rule.

However rights groups have ridiculed the charges as absurdly flimsy and based on tendentious evidence such as intercepted telephone calls and text messages merely criticising the government.

“Charging these Besiktas football club fans as enemies of the state for joining a public protest is a ludicrous travesty,” said Emma Sinclair-Webb, senior Turkey researcher at Human Rights Watch. “The indictment contains no evidence to support the coup attempt charges and should never have come to court,” she added in a statement.

Prosecutors have demanded life sentences for the accused, who are all currently not under arrest.

The indictment says the Carsi members tried to create an image similar to the “Arab Spring” by providing the foreign media with images of clashes.

As well as seeking to stage a coup, they have also been charged with acting as a criminal gang and resisting police.

The judge opened the trial by reading out the long list of defendants and then the charges, with supporters laughing loudly as every charge was read out, an AFP correspondent said.

Defence lawyer Efkan Bolac said the trial cannot take place in a state of law and said all the supporters had done was to counter attacks by police. “I expect the judges to rule in favour of the Carsi and swiftly deliver a ruling because otherwise it will be very embarrassing for our democracy.

“We don’t have any laws in place that say staging a protest amount to a coup attempt.”

The case has angered opponents of Erdogan who accuse him of showing ever greater authoritarian tendencies since becoming president in August.

Many posted statements of support on Twitter under the hashtag #Carsiyalnizdegildir (The Carsi is not alone).

“I’m a Galatasaray fan, but Carsi is something different,” said Sevin Duru, 31, outside the court, referring to Besiktas’ arch Istanbul rivals.

“This trial is like a summary of all the oppression we have been facing as young and brave people of this country. It is not about football, it is about freedoms.”

The protests began in May 2013 in Istanbul over plans to redevelop Gezi Park on Taksim Square in the centre of the city.

But they then snowballed into a nationwide wave of anger against the Islamic-rooted rule of Erdogan and his Justice and Development Party (AKP).

At least eight protesters were killed and 8,000 injured in a bloody police crackdown on the protests.

The oldest football club in Turkey, founded in 1903, Besiktas is still one of the top sides and plays in the Super Lig top division.

They will play English side Liverpool in the round of 32 of the Europa League - Europe’s second tier competition - in February.

The Carsi fan group is known for its strong support of the secularist principles laid down by modern Turkey’s founder Mustafa Kemal Ataturk as well as an adherence to hard left-wing politics.

The T-shirts of the Carsi (pronounced Charshi and meaning marketplace in Turkish) are adorned with the circular anarchist symbol. The group likes to boast that it is “against everything”.

Several trials related to the protests are already taking place across the country as well as a handful of cases of police accused of killing protesters.

More than two dozen alleged leaders of Taksim Solidarity - the main activist group behind the protests - went on trial in June, also facing lengthy prison terms for their part in leading the protests.