Pro-EU Warsaw mayor Rafal Trzaskowski holds rally ahead of Poland's presidential elections | AFP

Pro-EU Warsaw mayor and presidential candidate Rafal Trzaskowski holds one of his last rallies ahead of the first round of voting in Poland on May 18. Trzaskowski is the frontrunner, with around 30 percent of the vote in the latest opinion polls, compared with 25 percent for nationalist historian Karol Nawrocki.