Verhofstadt calls for more integration in bid for Commission top job

"We need a single energy market, not only because of the crisis in Ukraine but to be competitive again," he said. "We need to use the European Union's advantage of scale and integrated markets as an engine for growth."

Under the Lisbon Treaty, EU leaders are required to 'take account' of May's European parliament elections when selecting a candidate to head the Commission.

With the centre-right European People's party (EPP) and Europe's Socialists both likely to win between 200 and 220 of the 751 seats in the European Parliament, leaving both their respective candidates, Jean Claude Juncker and Martin Schulz, well short of a majority, Verhofstadt is hoping that he could emerge as a compromise candidate.

Verhofstadt, who currently leads the liberal (Alde) group in the European Parliament, accused Europe's conservatives of "irresponsible" complacency and socialists of believing "that it is possible to spend ourselves out of the crisis, denying that we have already huge debts and that these debts are at the origin of our problems".

During his nine year stint as prime minister of Belgium, Verhofstadt himself was vetoed by UK prime minister Tony Blair as being too federalist when touted as a possible chief of the EU executive in 2004. Jose Manuel Barroso, the current President, got the job instead.

Verhofstadt attempted to play down the perception that he would bid to increase the EU's powers, remarking that "it is not my ambition to decide the internal order of nation states".

Verhofstadt's pitch for greater EU integration goes against the grain of a campaign that has so far been dominated by populist, and often eurosceptic parties, from both the right and the left.

Opinion polls suggest that Verhofstadt's centrist group is set to suffer heavy losses at May's elections. Research by Pollwatch, which puts together voting intentions from the EU's 28 countries to produce a pan-EU poll, put the ALDE group on around 60 seats, down from the 83 MEPs it has in the current Parliament.

Its two largest delegations, the UK Liberal Democrats and German Free Democrats, are both expected to lose most of their seats.

However, although Verhofstadt's group of MEPs is likely to be outnumbered by the far-right, as well as the EPP and socialists, it is likely to retain its position as the third largest group in the EU's elected assembly, leaving the group as possible 'kingmakers'.

"I am optimistic we can avoid an institutional paralysis," Verhofstadt commented, although he warned that "if there's no majority in the parliament, then no one gets to be European Commission president." MEPs have the final vote on who becomes Commission President.

The first of several televised debates between the candidates will take place on Monday (28 April) in Maastricht.