European leaders are gathering in Brussels for a summit that is expected to be dominated by the specter of terrorism, following the bombings in Madrid two weeks ago. There is rising hope that the stalemate over a constitution for the expanding bloc can be broken in the months ahead.

The leaders of the European Union's 15 member states and the 10 others that will join the group in May are expected to adopt a series of measures aimed at bolstering Europe's fight against terrorism.

Some of the measures were approved two-and-one-half years ago, but have not been fully implemented. Others were drawn up during the past week by EU interior and foreign ministers.

British Foreign Secretary Jack Straw told his colleagues earlier this week that, after the Madrid attacks, terrorism must be at the top of the EU agenda.

"This is an area in which Europe's citizens are right to expect that the European Union and its member states will deliver results, and that's what we're doing," he said.

European officials admit that they must do better at exchanging information on potential terrorists and the ways in which they finance their activities or enlist new recruits. They also are insisting on a deadline for implementing European laws aimed at boosting police and judicial cooperation. Mr. Straw outlined what he expects to come out of the two-day summit.

"Strengthened law enforcement, and, also, an agreement that, by the 30 of June of this year, all the directives and changes in European law which were agreed in the aftermath of September 11, 2001 become domestic law in every European member state," he said.

Germany and Italy are among those countries that have dragged their feet on implementing EU anti-terrorist laws. For their part, Britain and France say they are not eager to share information across the board with all of their partners because they fear sensitive intelligence may end up in the wrong hands.

French Foreign Minister Dominique de Villepin says swapping information should be done on a case-by-case basis.

"Coordination is, of course, an absolute need, but widening the circle in the treatment of intelligence is something we should do very carefully," he said.

The last time they met in December, EU leaders quarreled over a proposed constitution that would facilitate decision-making once the EU expands to 25 members. The row centered on how much voting weight each country should have and pitted France and Germany against Spain and Poland, which demanded that their voting strength be nearly equal to that of bigger states.

Germany has now signaled a willingness to compromise. Spain's new prime minister is softening his country's stance, too. And Polish Foreign Minister Wlodzimierz Cimoszewicz says his country is ready to make a deal.

"We understand the logic of compromise," he said. "That means that everybody should adopt the same position and be ready to respect partners' expectations, partners' arguments."

The EU Irish presidency is now talking about a deal on the constitution being reached by June. But a lot of hard bargaining still lies ahead.