Since winning power back from the hands of his populist rivals a year and a half ago, Poland’s Prime Minister Donald Tusk has faced one very stubborn roadblock to his plans: the country’s president.

Poland will hold the first round of voting in its presidential election on Sunday. This is a hotly contested race between two main candidates – one from Civic Platform, the lead party in the ruling Civic Coalition, and the other an independent backed by the main opposition party, Law and Justice (PiS).

Poland’s presidential election will determine whether the country can restore the rule of law and remain a reliable partner in the European Union after nearly a decade of divisive right-wing populist rule.