"This standstill doesn't mean that time is standing still and that the EU is in some kind of frozen state. On the contrary. We see increasing return to national policies," Pahor said in his opening address to the Leaders' Panel.

The standstill also does not mean that everyone is waiting idle. "It's obvious that those who are not in favour of the future strengthening of the EU are moving on. And those of us who are in favour of such strengthening are standing still."

He warned that the standstill in institutional, political, economic and other forms of integration was making nationalist politics stronger.

"It seems that, at the moment, those of us who believe in a strong EU do not have a clear vision. However, its alternative appears to be clearer - restoring the power of the member states."

If those who believe in how important the EU is for peace, security and the well-being of Europeans fail to offer some sort of vision within a reasonable time, the European idea may fall in decline over the next five or ten years, Pahor warned.

The current standstill experienced by the EU will turn into a crisis if nationalist politics begins to prevail. "For now, this is not yet the case. However, it's becoming stronger than ever. It's undergoing a surge.

"Pro-European politics, fearing for its position, is adjusting to it. It's not providing an alternative. In my opinion, this can no longer continue. Some sort of political risk must be taken. We must expose ourselves," Pahor said.

Pahor also linked the issue to the EU's enlargement to the Western Balkans, saying that Slovenia was interested in seeing these efforts succeed. "A weak EU will not be enlarged to the Western Balkans," he said.

He again criticised the European Commission for failing to take a firm stand on the observance of European and international law with regard to the border between Slovenia and Croatia.

"Why would the Balkan countries try to reach an agreement if, in the Commission's opinion, such agreements do not need to be observed," the president wondered.