Internal bickering between the prime minister and the president of Poland has provided an interesting if somewhat undiplomatic sideshow at the summit. Prime Minister Donald Tusk and President Lech Kaczynski both insist they should be representing Poland at the talks.
Their dispute was there for all to see on Wednesday when Kaczynski, whom Tusk had denied a government plane, booked himself a last-minute charter flight and turned up at the talks.
A spare chair was found and the two sat awkwardly together. Tusk said the controversy over how the Polish delegation looked was not helping him to do his job.
Back home, polls suggest two-thirds of Poles believe Tusk should represent them at the summit, but almost the same number say he was wrong to deny the president a government flight.