Liberal Warsaw Mayor Rafal Trzaskowski and a conservative opponent, Karol Nawrocki, emerged ahead in a pack of 13 candidates.

If large urban centres are the core constituency of the liberal government of Polish Prime Minister Donald Tusk, then Sunday's presidential election first round showed him struggling against an anti-establishment pushback simmering throughout Europe.

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.