Jaroslaw Kaczynski, the twin brother of Poland's late president, declared his candidacy on Monday for a presidential election but political analysts said the combative nationalist was unlikely to win.
Poles are due to elect a new president on June 20 following the death of Lech Kaczynski, along with 95 other people, mostly senior Polish officials, in a plane crash in Russia on April 10.
Despite an upsurge of sympathy for the Kaczynski family, opinion polls show acting President Bronislaw Komorowski of the centrist Civic Platform as the most likely election winner.
Lech Kaczynski, elected president in 2005, had been expected to lose the election to Mr. Komorowski.
"In reality, it won't be him [Jaroslaw Kaczynski]running, it will be his brother. His campaign team will play on sympathy for his brother," said Krzysztof Bobinski, head of the Unia & Polska Foundation, a Warsaw think-tank.
"Kaczynski would have a chance to win only if other candidates make mistakes. This is a difficult situation for everybody. This is not a normal election campaign but I think political attitudes generally have not changed among voters."
Jaroslaw Kaczynski, a former prime minister who also heads Poland's main opposition party, the right-wing, eurosceptic Law and Justice (PiS), said he wanted to continue his brother's conservative mission.
"Poland is our great shared obligation. We are required to overcome our personal pain and to take on this mission despite the personal tragedy. That's why I have taken the decision to run for the presidency of Poland." he said in a statement.
Lech Kaczynski and his wife Maria were buried in state funeral in Krakow on April 18. Mr. Komorowski took over as acting President on Kaczynski's death in his capacity as speaker of parliament, the second highest ranking position in Poland's state hierarchy.
The decision to run will have been difficult for Mr. Kaczynski both personally and politically. Many Poles see him as a divisive figure whose spell as premier in 2006-7 put a strain on Poland's relations with Germany, Russia and the EU.
Polish media also say he has yet to tell his ailing 83-year-old mother of Lech's death.
The election outcome matters for Poland, the European Union's largest ex-communist member. Although Prime Minister Donald Tusk and his government hold most power, the president can veto laws and also has a say in foreign and security policy.
Lech Kaczynski had irked the Tusk government by blocking health, pension and media reforms. He and Jaroslaw had also resisted government efforts to push for the swift introduction of the euro in Poland.
A TNS OBOP opinion survey conducted on April 8-14 and published on Monday showed support for PiS had risen by nine percentage points since March to 33 per cent, though it still lagged Mr. Tusk's market-oriented, pro-euro PO on 52 per cent.
The Kaczynski twins were senior members of the pro-democracy Solidarity trade union that toppled communism in 1989. The union no longer has significant political clout but on Monday its leader, Janusz Sniadek, publicly backed Jaroslaw Kaczynski's presidential bid.
Other candidates for the presidential election include Waldemar Pawlak, whose Peasants' Party is the junior partner in Tusk's coalition government, and Grzegorz Napieralski, leader of the leftist SLD opposition party.
"After the recent events, Polish politics is a lot less predictable," said Rafal Chwedoruk of Warsaw University's Institute of Political Science.