His resignation came shortly after prosecutors announced raids on government buildings as part of an investigation into corruption.
Prime Minister António Costa of Portugal resigned unexpectedly on Tuesday, hours after the police raided government buildings and issued an arrest warrant for his chief of staff.
Prosecutors said the raids were part of an investigation into corruption.
In televised remarks, Mr. Costa said he had been “surprised” to learn that he will be the subject of criminal proceedings and that his “conscience is clear of any illicit or censured act.”
Mr. Costa has been in power since 2015.
This is a developing story and will be updated.