A judge in Venezuela has announced that imprisoned lawmaker Juan Requesens will face trial for allegedly trying to kill President Nicolás Maduro in 2018.
Mr Requesens was arrested three days after a drone carrying explosives blew up at a military parade attended by Mr Maduro on 4 August.
The opposition politician, who denies the charges, could face 30 years in prison if found guilty.
President Maduro was not hurt in the attack.
Who is Juan Requesens?
A former student leader who organised anti-government protests in 2014, Juan Requesens was elected to Venezuela's legislative, the National Assembly, in 2015.
The 30-year-old is a member of the opposition Primero Justicia (Justice First) party and a vocal opponent of President Maduro.
He often led protest marches demanding the release of imprisoned students.
What has he been charged with?
Mr Requesens faces two charges of attempted murder. He has also been accused of terrorism, treason, public incitement, illegal possession of a firearm, and conspiracy to commit a crime.
His lawyer, Joel García, said he had pleaded not guilty to all of them.
What do the charges relate to?
During the parade last August in the capital Caracas, a small drone carrying explosives detonated in the air not far from the stage where the president and the top officers of the military where standing.
Mr Maduro's bodyguards rushed to protect the president with foldable shields and ushered him away. The president and those on stage were unhurt.
Panic broke out among the soldiers on parade with many running for cover. Seven members of the National Guard were injured in the melee.
A second drone crashed into a nearby apartment block, injuring a child.
What was the reaction?
President Maduro was quick to blame Mr Requesens and another Primero Justicia politician, Julio Borges, for the drone attack. He said other suspects in the case had implicated the two lawmakers.
President Maduro called Mr Requesens "one of the craziest" plotters against his life.
Mr Borges, who was already living in exile at the time, dismissed the accusation as a "farce".
Did Mr Requesens confess?
Six days days after the drone attack, Information Minister Jorge Rodríguez called a news conference where he played a video which he said amounted to a confession by Mr Requesens.
In the recording, Mr Requesens says that Mr Borges asked him for help getting a retired soldier called Juan Monasterios into the country.
President Maduro had earlier accused Mr Monasterios, who was detained in the aftermath of the drone incident, of being the "operational chief" of the attack against him.
The video was the second one of Mr Requesens to be released. An earlier one showed him clad only in soiled underwear and looking confused.
That recording of Mr Requesens caused his family grave concern. They said the lawmaker appeared drugged and that they feared he had been tortured.
Where has Mr Requesens been?
Juan Requesens and his sister Rafaela were seized from their apartment in Caracas by members of the secret police on 7 August.
CCTV footage posted by Primero Justicia showed the moment the siblings were escorted out of the elevator.
Rafaela Requesens was later released but her brother has been in detention ever since.
His family has denounced the conditions he has been kept under and called for his release. His father, Juan Guillermo Requesens, met UN human rights chief Michelle Bachelet during her visit to Venezuela last month.
Ms Bachelet has called on the Venezuelan government to release all political prisoners but on Monday a judge ordered that Juan Requesens remain in detention while awaiting trial. A date for his trial has not yet been set.
Rights groups say Venezuela is holding more than 700 people for political reasons and that some of them are being tortured.
On Saturday, navy captain Rafael Acosta died in custody. His lawyer said his death was a result of torture and opposition leaders have called for mass protests to be held on Friday to denounce Capt Acosta's treatment.