Poland was eyeing a June election Wednesday to choose a successor to President Lech Kaczynski, whose death in an air crash is generating unprecedented scenes of public grief.
Mourners lined up through the night outside Warsaw's Presidential Palace to pay respects to Kaczynski, whose body is lying in state alongside that of his wife.
However, amid national unity in the wake of the disaster, there were the first signs of discord with protests reported over a decision to bury the late president and his wife in a crypt previously reserved for monarchs and saints.
The couple were among 96 Polish dignitaries, military top brass and officials who died when the plane carrying them to a service commemorating Polish prisoners of war massacred in Russia during World War II crashed in bad weather.
Their bodies were reptriated in emotional ceremonies early this week. Caskets carrying the bodies of 30 more crash victims were returned toÂ Poland on Wednesday aboard a military jet from Moscow.
The disaster has caused shockwaves through Poland, with thousands of people waiting up to eight hours to pay their respects to the first couple. Due to overwhelming demand, the palace was opened to the public through the night.
A line of up to 15,000 mourners, many dressed in black and carrying pictures of the deceased first couple, could be seen snaking through the center of Warsaw Wednesday.