Fine Gael leader Enda Kenny has called on the Taoiseach to end the uncertainty over the date of the Lisbon Treaty referendum.

Speaking on a visit to Brussels, where he was due to meet the European Commission President Jose Manuel Barroso, Mr Kenny said the enemies of a 'Yes' vote were complacency, confusion and lack of information.

He said the lack of a voting date was creating a vacuum in which  'anti-European groups' were allowed to spread misinformation about the treaty.

Mr Kenny said Fine Gael would put the nation and Europe first and would call on the public not to use the treaty vote as an excuse to punish the Government.

He added that Fianna Fáil had failed to do this when Fine Gael was in Government and signed the Anglo-Irish Agreement. Mr Kenny said on that occasion Fianna Fáil had undermined the treaty.

Mr Kenny also said he had no problem with the French far-right leader Jean Marie Le Pen coming to Ireland to campaign and he would not call on UCD Law Society to withdraw its invitation.

Fine Gael's campaign was already up and running, he said.

Mr Kenny said that an invitation extended to French President Nicholas Sarkozy and German Chancellor Angela Merkel was connected to a Dublin gathering of Fine Gael's European Parliamentary group, the EPP (European People's Party).

Mr Kenny said he did not envisage Mr Sarkozy and Mrs Merkel campaigning for the treaty on Grafton Street.

When asked if he would support the Taoiseach for any of the top new European posts envisaged by the Lisbon Treaty, Mr Kenny insisted he had said before that he did not 'regard Mr Ahern as fit for office at home, never mind abroad.'