"The fight against corruption is a great priority for Portugal and for me since the beginning of my mandate," de Sousa told journalists.
His comments come after it emerged that Portugal has the worst performance among Council of Europe member states in terms of implementing anti-bribery recommendations made by a watchdog set up by the body.
Recalling the support he had expressed for Portugal’s attorney-general, Lucília Gago, in her fight against corruption as a national priority, and for the autonomy of public prosecutors in all circumstances, de Sousa said advancing this fight represented "a conquest of Portuguese democracy ".
It is, he went on, “important to make this clear because we have the notion that, as we go further in investigating cases of corruption, the more we are responding to the appeal of Portuguese society and of democratic societies."
He added: "We can't stop [giving] that response."
Portugal has been found to be the country with the highest proportion (73%) of recommendations from the Group of States against Corruption (GRECO) that have not been implemented, followed only by Turkey (70%), according to the 2018 report of this Council of Europe anti-bribery monitoring body.
According to the report, which looks at the degree of implementation of recommendations to prevent corruption in the judiciary, Turkey leads the pack with 26 measures left unimplemented, followed by Portugal with 11, Greece with 10, Serbia with 10, and Belgium and Bosnia-Hergozina, both with eight.