European Commission president Jose Manuel Barroso publicly admits that Europe faces a danger of being sidelined unless it starts speaking with a strong and united voice.

Brussels – The European Union is hoping that its revamped leadership can reverse a decline in global influence, wary of being marginalised by the United States and emerging Asian powers such as China, experts said.

In a speech to the European parliament Tuesday, where he won approval for a new team of EU commissioners, Jose Manuel Barroso admitted there was a danger of European "insignificance" on the world stage "if Europe doesn't act more closely together."

"Europe counts when we speak with a strong and united voice ... It is less successful when we act according to narrow national interests, in an uncoordinated way," the European Commission president said.

But many observers are warning that Europe is struggling to have its voice heard and its message could be further muddied by its new multi-headed leadership structure.

Today "Europe is a negligible quantity on the international scene," warned Elie Barnavi, historian at the European museum in Brussels.

European officials are looking to the bloc's new Lisbon reform treaty, the fruit of a decade of wrangling, to update the functioning of a bloc which has swelled from 15 to 27 nations since 2004.

The treaty is also aimed at allowing the EU to speak with a more united voice.

However Barnavi and others are not convinced that the text, which creates the roles of EU Council President Herman Van Rompuy and foreign affairs High Commissioner Catherine Ashton, can achieve that.

"We have to recognise that Europe now has not one face but four," he told AFP in an interview; Van Rompuy, Ashton, Barroso and the rotating EU presidency currently held by Spain.

Added to that list are EU parliament president Jerzy Buzek, head of Europe's only elected body, as well as national leaders such as Germany's Angela Merkel and France's Nicolas Sarkozy.

Van Rompuy will on Thursday face his first major test as president, when he hosts a summit of EU leaders which he himself called.