President Andrzej Duda made the declaration at a news briefing on Wednesday.
The head of state told reporters he "will not rest" until the two jailed ex-ministers, Mariusz Kamiński and his former deputy Maciej Wąsik, are released from jail.
The two were detained at the presidential palace on Tuesday night and taken to prison to serve a two-year sentence for abuse of power when in charge of Poland's anti-corruption service CBA.
Duda said on Wednesday his pardoning of Kamiński and Wąsik in 2015 was "in line with the constitution," and "should stand."
Meanwhile, Interior Minister Marcin Kierwiński said the police had carried out the arrests "in a professional manner," executing a court order, "regardless of the fact that the case concerned well-known politicians," according to news outlets.
The case pits Prime Minister Donald Tusk's pro-European coalition, which is seeking to bring Poland back in line with European Union democratic standards and unblock tens of billions of euros in EU funding, against President Andrzej Duda, an ally of the conservative Law and Justice (PiS) party, which ruled Poland between 2015 and 2023, the Reuters news agency reported.
Lawyers for Kamiński are preparing a final appeal against his conviction to the Supreme Court, a cassation, aimed at acquittal, according to media reports.
On Wednesday, Kamiński said he had started a "hunger strike" against his imprisonment as a "political prisoner," and was later joined in his protest by Wąsik, the state PAP news agency reported.
On Wednesday evening, over a hundred people protested again in front of the presidential palace against the detentions, while some also came to support the decision to put the two ex-ministers in prison, according to news outlets.
Source: PAP, Reuters, RMF FM, rp.pl