The guarantee of holding on to a European Commissioner will be the carrot for the Republic to produce a ’Yes’ vote in a second Lisbon Treaty referendum late next year.

The Dublin government is considering a second vote in autumn 2009 — but this time with assurances on a commissioner, abortion, taxation and neutrality. The complex plan would involve extending the term of the current European Commission by several months. Irish voters would effectively be told their vote would save countries from occasionally losing their Commissioner — if the Government goes down this route.

After the resounding ’No’ vote last month, Irish government and European figures now acknowledge the prospects of Ireland sorting out its stance on Lisbon before next summer appear remote.

Critically, the referendum package would include EU assurances on the contentious issues of abortion, taxation and neutrality to head off concerns in each area.

The proposal is among the options being studied by the Government as it struggles to come up with a solution to the Lisbon dilemma.

Taoiseach Brian Cowen would have to inform his EU counterparts of the plan later in the year as it would have a direct impact on next year’s European Parliament elections and the appointment of a new European Commission.

Senior Irish government sources have indicated it is among the choices being looked at but it would need the co-operation of the rest of the EU. A source said: "You’d have to arrive at that decision by a logical means by the end of this year. It’s shaping that way. It’s being kicked around." The plan would involve:

l A European Commissioner for each country;

l A delay in the appointment of a new Commission;

l Written assurances of no interference on abortion, neutrality and tax;

l Some EU countries (not Ireland) losing more MEPs next year.

Without Ireland ratifying the Lisbon Treaty by next June, the European elections will have to be run under Nice Treaty rules, meaning a greater reduction in number of MEPs across Europe.

Spain would be the big loser under this development, but up to 12 countries would be affected.

Under the new Lisbon rules, the number of MEPs would drop from 785 to 751 but under the old Nice rules, the MEP numbers would fall from 785 to 736.

Either way, Ireland’s representation will be cut from 13 to 12, with Dublin losing one MEP.

Likewise, agreement would be required on the status of the European Commission, which is again due to reduce to less than one per country under Nice rules.