Power in Poland rests primarily with the prime minister and parliament. But the president wields real influence by signing laws into force, or vetoing them, appointing judges and ambassadors, and helping to shape foreign policy. Presidents can rarely impose their own agenda, but they can certainly frustrate the government’s.

Poland will hold the first round of a presidential election on May 18, setting the scene for a vote that will be crucial for the pro-European government's hopes of implementing its reformist agenda.

Polls open at 7 a.m. (0500 GMT) and close at 9 p.m. on May 18. Around 29 million people are eligible to vote. Exit polls will be published shortly after voting ends. Partial results will trickle in throughout the evening on Sunday and on Monday.