* Early opinion polls give supporters a clear lead

* Irish PM says investors now see Ireland in better light

DUBLIN, March 31 (Reuters) - Countries keen on investing in Ireland and aiding its economic recovery would quickly lose interest if voters rejected Europe's new fiscal treaty in an upcoming referendum, finance minister Michael Noonan warned on Saturday.

Ireland will hold what will probably be the only popular vote over German-led plans for stricter budget discipline on May 31 and the government is putting the country's economy and long-term stability at the front of its campaign.

Early opinion polls give supporters of the fiscal compact a clear lead but Noonan said a swing to the 'no' side would see countries like China, whose interest in Ireland has recently picked up, look elsewhere.

"This Treaty is a continuation of the confidence building in Ireland," Noonan said in a speech at senior governing party Fine Gael's national conference.

"We only need to look at the Taoiseach's (prime minister) successful visit to China earlier this week to see other countries want to invest in Ireland. If we were not so fully involved in the euro zone, they would not be interested."

A subsidiary of China's sovereign wealth fund on Tuesday signed a memorandum of understanding with Dublin's debt agency to explore investment opportunities in Ireland, but gave little detail on what it might be interested in.

Analysts said the $410 billion sovereign wealth fund would likely be interested in buying Irish assets and Dublin is keen to offload state-owned companies, stakes in all of its banks and billion of euro worth of property assets help by the state-run "bad bank".

With its domestic economy struggling to emerge from a devastating property crash, Ireland has also become increasingly reliant on attracting foreign companies like Google and Facebook into the country and Prime Minister Enda Kenny said its European Union membership was central to this.

"From my visits recently and over last number of months to other leaders and other countries, they make it very clear that their view of Ireland has changed utterly in the last nine months," Kenny told reporters on the sidelines of the party's conference.

"We're now in a very different position than we were a year ago and they do see Ireland's attractiveness as a location for investment and as a consequence jobs is linked inextricably to our central position as a member of the European Union."

The most recent poll on the referendum showed that 49 percent would vote in favour of the treaty with 33 percent opposed and 18 percent still to make up their minds.

• A Permanent Economic Emergency