Failure to solve the dispute over the constitutional treaty of the European Union would undermine the bloc's credibility, EU Commission President Jose Manuel Barroso said on Saturday.
At a joint press conference with Polish President Lech Kaczynski after their meeting, Barroso said the EU's internal relations must be handled properly if it wanted to enhance its public credibility.
He voiced the commission's support for Germany, which currently holds the rotating EU presidency, in the latter's efforts to solve the problem.
He also stressed the importance of getting consent from all EU members over a final solution to the problem.
Barroso hoped Poland would give "an active, positive, constructive contribution to the (search for) a solution to these institutional questions."
Kaczynski pledged Poland's "active" participation in the discussions on the EU treaty.
"I am personally convinced that by the preliminarily agreed target of 2009 we shall be able to speak in general of having resolved that problem," he said.
The EU's integration process was impeded in 2005 when France and the Netherlands, both founding fathers of the bloc, in their referendums rejected the bloc's constitutional treaty.
Poland is wary of the treaty's headlong rush to deepen the integration process, saying it is inconsistent with the EU's reality.
Germany has vowed to revive the constitutional process and asked Poland to make clear its attitude.
Under German Chancellor Angela Merkel's plan, a political deal has to be worked out over how the original text should be changed, while a full new text is expected to be ready by the end of this year and be ratified during the first half of 2009.