Lord Ashdown was Lib Dem leader for 11 years

Lord Ashdown told a Lib Dem conference fringe meeting: "It is not succeeding in the hearts and minds of people who are going to vote."

The former High Representative for Bosnia-Hercegovina also slammed Brussels as being "dysfunctional" and said its foreign policy was a mess.

He said allowing Bulgaria, Romania and other "western Balkan" nations to join the EU would help fight UK crime.

'Fortress mentality'

Lord Ashdown was speaking at the Lib Dem European group's meeting in Brighton.

He said the European Union was the world's most successful peace stabiliser and nation builder.

But it was also the world's first genuine "supranational" institution.

"This has to succeed," he said. "I have to tell you it's not succeeding."

He complained that a "fortress Europe" was emerging which was focusing on defending itself rather than looking outwards.

He was asked whether Romania and Bulgaria would add value or be a burden to the EU.

The two nations are due to join next year and the UK Government has yet to decide whether there will be work restrictions on Romanian and Bulgarian migrants.

Eastern frontier?

Lord Ashdown said the two nations would add value but Europe had to address three intertwined issues.

He said a decision had to be made on defining the eastern limit of the EU.

"I don't think we're going to get permission from our people unless European Union leaders are prepared fairly soon to define where the eastern limit is," said Lord Ashdown.

People had often thought that Bosnia-Hercegovina was a dysfunctional state, he said.

"It was not half as dysfunctional as Brussels when I used to go there," he said.

Tackling crime

Lord Ashdown said the EU must take in the western Balkans - countries like Romania, Bulgaria, Macedonia, Albania, Serbia and Montenegro, and Bosnia-Hercegovina.

Failure to do so could see a repeat of the instability which had time and again come from the region.

And crime would not be tackled in a region through which 70% of trafficked women came.

"If you want to tackle crime in central Manchester, Berlin or Paris, then you need to tackle the rule of law in some of those western Balkan countries," he said.

Lord Ashdown said incorporating the region into the EU was "unfinished business in a project to which we have already set our hands".

One delegate claimed a "mafia gang" from Romania or Bulgaria had settled close to her house.

But Lord Ashdown suggested such problems could be solved by making western Balkan countries meet the EU's entry conditions, as had happened with other nations.

Crime gangs were better tackled "at source rather than having to do it in your backyard".