Poland's president has postponed a ceremony marking a wartime massacre after being accused of manipulating the event for electoral gain.
The massacre at Katyn still arouses controversy in Poland
The commemoration of the Katyn massacre will now take place in November, after rather than before, this month's polls.
The move reverses an earlier attempt to bring the ceremony forward to Friday, which had led to claims the government was trying to politicise the massacre.
Soviet forces executed thousands of Polish officers at Katyn in 1940.
The massacre, which followed Moscow's deal with Nazi Germany to invade and divide Poland, remains a sensitive episode in Polish history.
Relatives of some of the prisoners killed in the Katyn forest - including the acclaimed film maker, Andrzej Wajda - had joined opposition politicians in criticising the president's original plan to bring the commemoration forward.
They said the president's move had been designed to favour his twin brother, Prime Minister Jaroslaw Kaczynski, whose Law and Justice Party is fighting the election on a nationalist platform.
The party also has a reputation for anti-Soviet sentiment.
President Lech Kaczynski's office announced on Thursday that it had decided to reschedule the ceremony for November, and rejected claims it had tried to make political capital out of the event.
"Unfortunately, the president's motives were falsely interpreted and the ceremony was dragged into the election campaign," presidential aide Ewa Junczyk-Ziomecka told the Reuters news agency.
"President Kaczynski could not allow such treatment of victims, their families and the country's highest authority," she said.
Earlier, the president's office said it had brought the ceremony forward to coincide with the release of Andrzej Wajda's film about the Katyn massacre.
But Mr Wajda, whose father was among those killed, attacked the decision to hold the commemoration before the election.
"This promotion will be taking place during an electoral battle," he said, referring to plans to hold a ceremony where some of the massacre victims would receive posthumous promotions.
"I don't want the death of my father, and the deaths of the thousands of Polish officers exterminated in the Soviet Union, to be exploited," Mr Wajda said.
The ceremony will now take place on 11 November, Poland's independence day, which comes three weeks after the election on 21 October.