Fine Gael leader Enda Kenny has called on farming leaders to give a "clear direction" to farmers that they should vote Yes to the constitutional referendum on the Lisbon Treaty.
Unveiling a billboard campaign in support of the treaty today, Mr Kenny urged farmers to separate the issues involved in world trade talks from the issues in the treaty.
"If you didn't have a Lisbon Treaty to decide on, you would still have to deal with the world trade talks," Mr Kenny said.
"My point is that you are far better able to deal with the consequences of the conclusion of the WTO, by having endorsed a stronger European platform by having voted Yes for the referendum."
Mr Kenny said that at a meeting in Brussels yesterday of the European People's Party - the European-level grouping of which Fine Gael is a member a clear message had been sent to the European Commission that it must "stay within its negotiating mandate" in the trade talks.
He said the Commission had been told it should not accept any WTO deal that does not respect the European model of agriculture and one that protects food security.
Irish Farmers' Association assistant general secretary Brian Barry said yesterday that farmers needed a guarantee that an unacceptable trade deal would be blocked.
The European Commission made it clear, however, that the Government would be able to veto World Trade Organisation talks if it unhappy with the impact such an agreement could have on Irish agriculture.
Mr Kenny said he looked forward to "very vigorous" engagement during the referendum campaign.
"We have invited all and sundry - persons with a different opinion than us - to our meetings, where the issues that are in the treaty can be debated rationally and comprehensively. All our people are attempting to answer those questions for everybody in the fullest possible manner."
The Fine Gael leader conceded it was difficult to get a very high level of interest in any referendum "unless it's the Good Friday Agreement".
"But in this case, our meetings have ranged from 80 to 300 in size. Some have been very vigorous, where there have been different opinions expressed and I think that's been very healthy in the sense that people feel engaged in the political process."
Mr Kenny said he believed the treaty referendum will be passed.
"I believe at the end of the day when people look at what's in this treaty, they will say that this actually is about the bigger picture, it's about the opportunities and the challenges for the next generation of our children coming behind us, who are going to be the drivers of Ireland in the next 25 years."
He said the treaty was about putting the political framework in place so that the European Union was capable of working for 500 million people, instead of 250 million.
Sinn Féin said Mr Kenny had shown a “lack of understanding” of the Lisbon Treaty.
Agriculture spokesman Martin Ferris said the treaty provisions on qualified majority voting "unquestionably removes Ireland’s ability to veto decisions not in its interest".
Taoiseach Brian Cowen said today that European Union has never threatened Ireland's independence and that respect for small countries is "in the DNA" of the Lisbon Treaty.
Speaking in Kilkenny at the start of a Fianna Fáil tour of the country to promote a Yes vote, Mr Cowen said it was important for people to "stand back" and look at what lies behind the treaty.
"The history of Ireland's membership of the Union shows that it has never threatened our independence, it has actually secured our independence.
"We have been able to build a successful state which is in charge of its own destiny - but equally we have been given an opportunity to shape European and world factors in a way that would be impossible if we stood isolated at the edge of Europe."
"Faced with the challenges of globalisation, climate change and cross-border crime smaller countries need a Union which is efficient and effective because it is the only way we can influence issues which are fundamental to our future."