'National leaders are concerned Mr Van Rompuy, who had been expected to take a back seat role, is attempting to expand his position.

Germany and France backed his candidature on the understanding he would act as an EU "chairman" rather than a high-profile leader.
 
But the introduction of the Lisbon Treaty has triggered bitter in-fighting between Mr Van Rompuy, Baroness Ashton, the foreign minister, and the Commission over who is in charge of representing Europe on the global stage.

Diplomats are increasingly worried that amid the turf wars there is a danger of Brussels "mission creep" as squabbling EU chiefs try to enlarge their empires at the expense of each other and national sovereignty.

National governments, led by Germany, are incensed by an attempt by Mr Van Rompuy to take on new powers he claims were agreed at an informal summit two weeks ago.'

Read more: War in the EU as Herman Van Rompuy Makes 'Power Grab'