(ANSA) - WARSAW, 18 MAG - Pro-European candidate and Warsaw mayor Rafał Trzaskowski, of Premier Donald Tusk's Democratic and Liberal Party Civic Platform, is leading in the first round of presidential elections in Poland, registering 30.8 percent of the vote, while his rival Karol Nawrocki supported by the Pis, the party of former premier Mateusz Morawiecki, received 29.1 percent of the vote, according to exit polls conducted by the Ipsos Institute. The runoff between the two candidates will take place on June 1. (ANSA).