Polish president Aleksander Kwasniewski met with Germany's chancellor, Gerhard Schroeder, to defend Poland's position against proposals that distribution of votes in the European Commission should be proportional to the size of population of member states.
Under current rules, Poland and Spain have almost as many votes as countries such as Germany and France, which have much bigger populations.
"If the position is what is in the treaty, without the chance for compromise, we cannot say yes," Kwasniewski told the BBC.
Italian Prime Minister Silvio Berlusconi, whose country holds the rotating EU presidency, said Wednesday he had a plan to break the deadlock, but would not reveal it yet.
The dispute centers on a promise won by Poland and Spain at the Nice summit in 2000, giving them 27 votes each on Europe's powerful Council of Ministers.
That compares with 29 for Germany, which has double the population.