LIBERTAS, the Declan Ganley-led group that successfully opposed the Lisbon Referendum, may contest next year's European elections, not just in Ireland, but across the EU, if an attempt is made to 'rail-road' through the Lisbon treaty.

Ganley declined to rule in or rule out contesting the elections yesterday, but other political parties are fully expecting Libertas to remain active.

And it is understood that rolling out Libertas on a pan-European basis may be an option if what the group has described as the unaccountable and undemocratic basis of the Lisbon treaty is not reformed.

Sources stress it is very early days yet and Libertas has no plans in place beyond last Thursday's referendum.

They also say if the EU authorities respond in the right manner to the treaty's defeat in Ireland, they will regard their mission as complete.

However, renegotiation of the Lisbon treaty is regarded as a non-runner and Libertas is likely to strongly oppose efforts to press ahead with the treaty in, or close to, its current form.

The group has had a flood of calls of support from across the EU since the No result. The opportunity of providing what it would see as a moderate, democratic voice on a pan-European basis is likely to appeal.

Meanwhile, sources on the defeated Yes side are this weekend warning Ireland may lose its EU commissioner from next year as part of the fallout from Thursday's no vote.

One of the key arguments of the No side was each state's loss of a commissioner, from 2014, for five out of every 15 years on a rotation basis. However, the Yes side says that under the Nice treaty – which the EU will revert to if Lisbon is abandoned – there is still a requirement to reduce the number of commissioners, but to do so from 2009 instead of 2014.

While there is no system in place to reduce the numbers, the Yes side predict it will be done on a rotation basis.

"And guess who's going to go first in giving up a commissioner?" one source asked rhetorically.

French president Nicolas Sarkozy said yesterday that, following the no vote, EU member states must continue ratifying the Lisbon treaty to avoid a crisis.

"The others must continue ratification… so that the Irish incident does not become a crisis," Sarkozy said.

However, it is clear that, despite suggestions across Europe, there is resistance among the main Irish political parties to the idea of a second referendum here on Lisbon.

Sources close to Labour leader Eamon Gilmore made it clear yesterday his party strongly opposes this option. The relatively high turnout last Thursday, combined with a lack of obvious changes that can made to placate No voters, means this view is likely to be shared by the other main political parties.