Portuguese prosecutors opened an investigation Saturday into the legality of the government's authorization of U.S. use of the Lajes Air Base in the Azores during the Iran conflict, Reuters reported.
The probe follows a complaint by members of the opposition Left Bloc, which argued that the U.S. use of the base amounted to a “gross violation of international law.”
Under a longstanding agreement with the U.S., Washington can use Lajes without prior Portuguese authorization during peacetime, but Portugal's approval is required once hostilities begin.
Portugal, unlike neighboring Spain, authorized several U.S. transit flights through the base, prompting criticism from left-wing opposition parties and a political debate over Lisbon's role in operations linked to the conflict with Iran.
“The probe was opened following a complaint filed by members of the Left Bloc party,” Portugal's Prosecutor General's Office said, without providing further details.
The Left Bloc asked prosecutors in April to investigate the U.S. use of the Lajes base.
Portugal's Foreign Ministry declined to comment.
Foreign Minister Paulo Rangel has said Portugal was not involved in the conflict and maintained that the use of the base complied with international law.
He said authorization was granted only after Washington assured Lisbon that any operation would be defensive, necessary and proportionate, and limited to military targets.
Portuguese prosecutors operate under the principle of legality, meaning they are required to investigate alleged wrongdoing when sufficient grounds exist, unlike jurisdictions where prosecutors have broader discretion over whether a case should proceed.
Lajes Air Base is located in Portugal's Atlantic Azores archipelago and serves as a strategic transit hub for U.S. forces.
Its role is governed by a bilateral defense treaty dating to 1951.
The base hosts the U.S. Air Force's 65th Air Base Wing and provides support for U.S., NATO and allied operations.