PM Tusk: convicts have found comfort at the presidential palace; the president is obstructing justice

The accusations were the latest salvo in a row that is likely to be one of many during a period of cohabitation, where the government and head of state are from different political camps.

In 2015, weeks after the nationalist Law and Justice (PiS) party came to power, Duda issued a pardon to PiS party member Mariusz Kamiński after he was convicted of abuse of power in a previous role as head of Poland's Central Anti-Corruption Bureau, allowing him to become interior minister. Kamiński had been accused of allowing agents under his command to use entrapment in an investigation.

Lawyers questioned whether Duda could pardon him before an appeals court issued a final ruling. The Supreme Court said last year the case should be reopened and in December Kamiński and his deputy Maciej Wąsik were sentenced to two years in prison for abuse of power.

Prime Minister Donald Tusk said both Duda and PiS leader Jarosław Kaczyński could be held responsible for obstructing justice.

"The situation is unbelievable. Convicts ... are to be taken to a place of solitary confinement, but they choose another, more comfortable place of solitary confinement - the presidential palace," Tusk said.

According to the head of government, "today we have to deal with an attempt to build a diarchy and the involvement of main institutions". "It is obvious sabotage. I am very, very concerned about this. And it’s not about Mr Wąsik or Mr Kamiński; that’s the court's decision, that’s the work of the police."

"I do not have to explain to anyone the current situation in which Poland and Europe find themselves today. The challenges ahead of us are immense, ranging from those related to war to internal issues concerning the security and development of Poland. We have a portfolio of projects, and almost each of them signifies a better life for the people. We are determined to move forward with these initiatives. However, under such chaotic circumstances and diarchy, it will be very difficult, if not impossible," Tusk argued.

"This dispute arises from the belief that the first pardon (by president Duda - edit.) was ineffective, and therefore, it should be reopened. No one would be bothering him (the president - edit.) about it, and he could put an end to this unnecessary show. However, as I mentioned, it is not my role," the prime minister added.

On Tuesday, the president's office posted a picture of Kamiński and Wąsik with Duda at an official event at the palace.

"A sombre dictatorship is being formed. We cannot allow for Poland to hold political prisoners," Kamiński said after the event, before reentering the building.

"We are dealing with a deep crisis of our state, a rebellion in the courts ... we are not hiding, we are at the president's," he added.

Polish court says two members of former government should go to prison. The police have been ordered to detain Kamiński and Wąsik and transfer them to a penitentiary facility.

Grażyna Ignaczak-Bandych, the head of the president's chancellery, told the Interia news website that the cars of presidential aides had been stopped and searched by police when leaving the palace.

"This is unauthorised interference, we will demand explanations," she was quoted as saying.