Warsaw  - Polish President Lech Kaczynski will sign the Lisbon Treaty on Saturday, his chief of staff said, after earlier confusion over when the country would ratify the key EU deal.

Wladyslaw Stasiak said that a signing ceremony would take place at 12:00 pm (1000 GMT) at the presidential palace in Warsaw on Saturday. Earlier, Jerzy Buzek, president of the European Parliament had said that invitations for a signing ceremony had been sent out to European Commission President Jose Manuel Barroso and Swedish Prime Minister Fredrik Reinfeldt.

However Barrosso's office said Thursday it had not received an invitation, and Reinfeldt's office could not confirm that the Swedish leader had received an invitation.

After Kaczynski's signature, Czech President Vaclav Klaus will be the sole European leader who has yet to ratify the treaty, which must first get approval from the Czech Republic's Constitutional Court.

The treaty needs unanimous approval from the 27-member bloc before it can be implemented.

Earlier, top Kaczynski aide Aleksander Szczyglo told TVN24 that Kaczynski would ratify the controversial reform treaty on Sunday evening, but the president's twin brother, Jaroslaw Kaczynski, quickly denied the report.

"The president keeps his word," Szczyglo told the news broadcaster. "He announced many times that if the Irish say 'Yes' in a second referendum, then his decision will be positive."

The Polish president's brother, who heads the opposition Law and Justice party, told journalists not to "believe gossip" that the ceremony would be Sunday. He called Szczyglo "poorly informed."

Kaczynski had pledged to sign the treaty soon after it was approved Irish voters. dpa