Brussels  - European Commission President Jose Manuel Barroso hopes the appointment of Brian Cowen as Ireland's new prime minister can help rally support for the EU's Lisbon treaty in next month's referendum there.

In a message of congratulation Thursday, the commission chief said Cowen's appointment comes "at an important time for Ireland and for Europe, with the Irish referendum on the Lisbon Treaty coming up on June 12."

"I welcome your very evident support for the treaty and your determination to do everything in your power to try to ensure a positive result on referendum day," he added.

Latest opinion polls suggest a three-way split among Irish voters, with about a third of them expressing support for the EU treaty, a third against it and a final third still undecided.

Ireland is the only EU country to vote in a referendum to ratify the reform treaty, which has already been ratified by 13 member states.

Should the Irish reject the treaty, it would scupper plans by officials in Brussels to have the text come into force next year.

Cowen was sworn in as prime minister on Wednesday after Bertie Ahern stepped down a day earlier amid allegations about his personal finances.

Some political analysts had said the Irish might have used the referendum on the reform treaty to express their disapproval at Ahern's conduct. (dpa)