European Council President Herman Van Rompuy was hosted a phone call on Friday between the leaders of Germany, Italy, France, Britain and Spain ahead of next week's meeting of the Group of 20 leading industrial nations, his spokesman said on Friday.
One EU official, speaking on condition of anonymity, said the leaders used the call to discuss deeper European economic integration, including the degree to which it should involve all 27 members of the European Union or the 17 countries in the eurozone.
Van Rompuy, Commission President José Manuel Barroso, European Central Bank President Mario Draghi, and Eurogroup Chairman Jean-Claude Juncker have been given the task of reporting on closer eurozone integration to a leaders' summit on June 28-29.
The eurozone's plans to move towards a banking and fiscal union should help market confidence, but investors must give Europe time for the process, EU Economic and Monetary Affairs Commissioner Olli Rehn said on Friday.
"We need to map out the direction and steps towards a full economic union to complete our monetary union, including through a financial union," Rehn said. "Demonstrating the political commitment of member states to the euro will be a key part of restoring confidence in the euro area," he said.
He said the main elements of a financial union would include a single rule book on capital requirements, integrated financial supervision, a common resolution authority and a single deposit insurance scheme.
"All these common and integrated elements should be put together into the same overall framework, intended for the 27 member states, while allowing deeper integration and stronger requirements for the euro area as necessary," he said.
While the economic integration process is likely to be politically difficult and take years, it would lead, in the end, to joint eurozone debt issuance – which markets would very much welcome.