In a dramatic escalation of Poland’s battle to restore the rule of lawpolice entered the country’s presidential palace on Tuesday night and arrested former interior minister Mariusz Kaminski and his associate Maciej Vojšić who were hiding under the protection of the president Andzey Duda after they were sentenced to prison terms for abuse of power.

The arrests reflect the battle between Duda and the new prime minister Donald Tusk, who seeks to reverse the missteps of eight years of rule by the nationalist, conservative Law and Justice Party (PiS) and exclude loyalists of the previous government from key institutions such as the media, courts and state-owned companies.

Duda still, however, POLITICO writes, still has significant ability to block Tusk’s reform efforts. The case of the two convicted PiS MPs who enjoyed presidential protection quickly became a point of reference in the battle between the two camps, until the police made arrests.

Tusk’s new government, which won elections in October, wants to reshape the country to bring it back into line with EU democratic rules, unlocking billions in frozen EU funds and making Warsaw a European power again.