After President Lech Kaczyński 's death in a plane crash on 10 April 2010 , the Constitution required the Marshal of the Sejm to declare the date within two weeks , with the election to take place on a weekend within the following 60 days , i.e. 20 June at the latest . On 21 April , the Marshal , Bronisław Komorowski , announced the election date as 20 June 2010 . Candidates were required to register by 26 April 2010 ( with 1,000 signatures of voters in support ) and submit 100,000 signatures by 6 May 2010
a plane crash
2010 Polish Air Force Tu-154 crash
2010 Polish presidential election