President Barroso congratulated the two. “I think it will be impossible to have a better choice than those personalities for the European Union leadership.”

A Christian-Democrat politician and economist by training, Mr Van Rompuy, 62, has served as Belgium’s premier for nearly a year. Many credit him with bringing stability to the country during tensions between the French- and Flemish-speaking communities.

“I have not sought this high position. I have intervened in no way. But from tonight, I will take it up with conviction,” he said.

In an agreement with the European commission, the council appointed Catherine Ashton, 53, to be the EU’s high representative for foreign affairs and security policy. A member of the UK Labour Party, she will also serve as a vice-president of the next commission now being formed.

The two posts were created by the recently approved Lisbon treaty, which aims to enhance the EU’s role in world affairs and streamline its decision-making.

The new president will serve for 2½ years. The position will replace the rotating presidency under which one member country chairs major EU meetings for six months.

Van Rompuy’s core responsibilities will include chairing council meetings and representing EU leaders on the global stage. He will also represent the council in relations with other EU institutions.

Catherine Ashton will have the authority to propose defence and security measures. She will also be tasked with setting up a network of diplomats around the world to support the new office.

She said she was surprised by her nomination, which must still be confirmed by parliament. “I am very honoured and proud to have been asked to take on this role. ”

“I will make sure I represent our values across the world.”

The post of high representative merges two existing portfolios: high-representative for common foreign and security policy and commissioner for external relations.

The selections become official with the entry into force of the Lisbon treaty on 1 December.