European Union leaders voiced optimism tonight they would overcome objections raised by Poland and others to clinch a deal on a treaty to reform the bloc's institutions.
Warsaw, which before the start of the two-day summit in Lisbon had threatened to delay the talks if its demands on new voting arrangements were not met, said it now saw "a big chance" of a deal to end a decade of wrangling over EU structures.
"If I were to assess in per cent terms it would be 80-90," Robert Draba, secretary of state at the Polish president's chancellery, told reporters as leaders began the first session of talks in the Portuguese capital.
Portuguese prime minister Jose Socrates, chairman of the two-day summit, said he was very confident of a deal.
"I think we are getting very, very close to a new treaty and this will be called the Lisbon Treaty," he told reporters after a pre-summit meeting with trade union and employers' leaders.
Agreement would end a crisis of confidence sparked by Dutch and French voters' rejection of a European constitution in 2005 and open the way for a toned-down treaty that includes a foreign policy chief with more clout and a long-term EU president.
The treaty also provides a more democratic decision-making system and more say for the European and national parliaments but omits mention of an EU constitution, anthem or flag.
Poland, which fought against the changed voting system at a summit in June, has recently voiced greater optimism that it would win a compromise on its demands.