ANKARA (Reuters) - Turkey will retry a lawmaker from the main opposition party after a court annulled his 25-year prison sentence but he will remain in custody, broadcaster NTV and opposition lawmakers said on Monday.

Enis Berberoglu became a symbol for more than 50,000 people detained in the wake of a failed coup in July 2016.

The chairman of his secular Republican People’s Party (CHP) started a 425 km (265 mile) protest march from the capital Ankara to Istanbul when he was convicted and sentenced in June for military espionage.

The court had said Berberoglu gave an opposition newspaper a video purporting to show Turkey’s intelligence agency trucking weapons into Syria.

Monday’s decision to cancel the sentence came from the regional court of appeals, broadcaster NTV said.

Berberoglu was the first CHP lawmaker to be jailed in a crackdown by President Tayyip Erdogan’s government that has raised concerns among Turkey’s Western allies and rights groups.

More than 150,000 people, including teachers, academics and lawyers, have also been suspended from their jobs. Around 150 media outlets have also been shut and some 160 journalists jailed, the Turkish Journalists Association says.

A prosecutor has called for jail sentences of up to 15 years on terrorism charges for rights activists including the local head of Amnesty International, Amnesty said on Sunday.

Critics say Turkey is sliding toward greater authoritarianism. The government says such measures are necessary, given the vast security threats it is facing.