"We are now at two years on since the signing of the constitution," he told EUobserver. "It is about time we pressed on with Plan B."

In the rescue plan, the MEP staunchly defends the core of the existing EU constitution text – part I on institutional reform and part II on fundamental rights - while making the document more attractive to citizens by adding provisions which specifically address their concerns.

"We have to try to understand the causes of the disaffection which was expressed in France and the Netherlands and elsewhere," he said.

"I think if one does, and I have, there are five elements which stand out," he argued referring to the economic governance of the union; Europe's social model; sustainable development and climate change policy; enlargement policy; and the reform of the EU's finances.

The Duff plan proposes adding fresh clauses on these five policy areas to the constitution by opening up the current policy part of the text, part III, while leaving parts I and II as they are.

Sarkozy and Amato

The MEP insists that simply removing the entire or most of part III – as proposed by French interior minister Nicolas Sarkozy and others - is not enough. "Subediting is not a sufficient response to the crisis," he said explaining that the changes to text should be "political."

Mr Duff rejected various proposals to merely slim down the constitution text without adding anything new - which he said are also under discussion in the "wise" group of European politicians led by Italian interior minister Giuliano Amato.

"I suspect that the Amato group is to come out with a...simple filleting of part III," he said. "This is mere pathology...What I am trying to do is to rejuvenate the creature."

The British MEP also opposes ideas to drop the name "constitution" and instead call a revised text a "treaty." Such a move would merely spark "contempt" from citizens while disguising the "truth about the scale and scope of integration," he said.

Liberal divisions

Meanwhile, Mr Duff's fellow European liberal party (ELDR) members gathering in Bucharest on Thursday and Friday (12-13 October) failed to reach agreement on a liberal "vision" on the future of the EU following disagreement on key paragraphs on the constitution.

ELDR president and Belgian MEP Annemie Neyts had in the run-up to the congress prepared a draft "vision for a modern and motivating EU" but the document was rejected by member parties and shelved until May next year.

The draft stood in sharp contrast with Mr Duff's plan B, as it said that "a revised text should not be called a 'Constitution'."

The ELDR draft also questioned the institutional Part I of the constitution by stating that "issues such as reducing the size of the Commission...and creating the position of EU President could be removed from the text."

Two-draft referendum

Eurosceptics in the European Parliament, meanwhile, are criticising the recent wave of plans to resuscitate the EU constitution, with Danish member Jens-Peter Bonde stating "instead of manipulating the public by drafting a compressed constitution, we should make a fresh start."

The veteran MEP proposes setting up a new "convention," similar to the body of European politicians that drafted the constitution but this time "directly elected by the people."

The body would have 270 members - with 10 representatives per member state - and work for one year, ideally coming up with two draft treaties - "draft A for a kind of EU state and draft B for a Europe of democracies."

Voters would subsequently be able to choose between the two options - representing radically different scales of European co-operation - in an EU-wide referendum.

"If people go for the federalist option I will accept that," he said adding that he would himself promote draft B - a decentralised EU focusing its work strictly on cross-border issues.