(DUBLIN) - New Irish Prime Minister Brian Cowen launched an election-style campaign Monday calling for a "Yes" vote in a crunch referendum on the EU's Reform Treaty next month.

The June 12 plebiscite -- which could throw the European Union into crisis if it rejects the new treaty -- will be the first electoral test for Cowen, who took over from veteran premier Bertie Ahern last week.

Cowen pledged every section of his Fianna Fail party would distribute leaflets and canvass door-to-door in support of the Lisbon treaty, which has replaced the doomed EU constitution.

"Every public representative will participate. Every member of government is committed to full participation in the campaign. I and other members of the government will undertake a national tour in the campaign bus."

Of "No" campaigners, he said: "We have no intention of standing back and letting them distort the Treaty or demonise a Union which is so important to the success of modern Ireland."

Ireland is the only one of the EU nations due to vote on the treaty, and a "No" vote could scupper it altogether.

The treaty -- replacing the bloc's doomed constitution after its rejection by French and Dutch voters in 2005 -- was agreed last December amid much fanfare.

It aims to prevent decision-making gridlock in the expanding bloc.

All the main Irish political parties are backing the treaty, with only the republican Sinn Fein against.

The "Yes" side received a weekend boost when the latest opinion poll showing support was up three points to 38 percent in the last fortnight. "No" support was down three points to 28 percent and the undecideds remained at 34 percent.

In 2001, Ireland sent shockwaves through the bloc when it rejected the EU's previous Nice Treaty on institutional reform and enlargement. That decision was reversed in another referendum.

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