"#ECJ: a person elected to the #EP acquires the status of MEP at the time of the official declaration of the results and enjoys, form that time, the immunities attached to that status #Junqueras @junqueras (press release will follow)," the ECJ Tweeted.
The sentence, read by the president of the ECJ Koen Lenarts, said: "Persons who, like Mr. Junqueras Vies, have been elected Members of the European Parliament enjoy, from the moment the results are declared, the immunity as regards travel which is attached to their status as Member and provided for in the second paragraph of Article 9 of the Protocol," Efe news reported.
The court added that the purpose of the legislation was to allow MEPs to travel to the Eurochamber and participate in sessions.
Junqueras, the former deputy leader of the regional Catalan government, was elected to the European Parliament on May 26.
He had been in provisional detention before the elections took place due to his involvement in the Catalan referendum on independence, which took place on 1 October 2017.
On October 14, Junqueras was found guilty of sedition and misuse of public funds and sentenced to 13 years. He was also banned from holding public office for another 13 years.
Since being elected, he has not participated in EP sessions.
Thursday's ruling added that if the Spanish Supreme Court considered it necessary to maintain Junqueras in provisional imprisonment, it would have to lodge a request to the EP to suspend his immunity.
The ECJ's ruling backed Junqueras and rejected the Spanish government's view that the Catalan is not a consolidated MEP and should not enjoy immunity having failed to complete procedures required by Spanish law, despite being an elected member of the EP.
Junqueras was among a group of nine Catalan politic and activists who were convicted by Spain's Supreme Court.
The convicted politic and activists were found guilty of staging an unauthorized referendum on Catalan independence.
The illegal ballot brought Spain to the brink of a constitutional crisis. In response, the government at the time triggered a constitutional article to sack the regional Catalan government, dissolved parliament, temporarily suspend the region's autonomous status and opened the path for legal proceedings against the accused.
Spain's Constitutional Court, the country's highest judicial rung, had ruled the referendum unconstitutional.
( With inputs from IANS )