Analysis: Key differences have narrowed since last December, writes Denis Staunton in Brussels.
Last night's decision by European Union leaders to seek an early deal on the constitutional treaty is a tribute to the impressive work of the Irish Presidency during its first three months.
Differences over a number of key issues have narrowed since last December's EU summit collapsed and the shock of the Madrid terrorist attack has added a new urgency to the search for agreement.
The task ahead remains formidable, however, and there is no guarantee that Ireland will succeed where Italy failed in persuading all 25 governments to agree on a final text.
The most difficult issue remains the reform of the voting system in the Council of Ministers, where national governments meet. Spain and Poland have dropped their opposition to replacing the system of weighted votes agreed at Nice with a "double majority" based on population size.
The draft treaty approved by the Convention on the Future of Europe defines a qualified majority as a majority of member-states representing at least 60 per cent of the EU's population. The difficulty some countries have with this formula is that it would allow the EU's three biggest states - Germany, France and Britain, which comprise 42 per cent of the EU's population - to block any decision.
Germany indicated last month that it could accept a double majority defined as 55 per cent of member-states representing at least 55 per cent of the EU's population. Other countries have argued for a higher population threshold, although some governments argue that the threshold should not be so high as to make decision-making too difficult.
Some diplomats suggested this week that a double majority could be accompanied by a rule that a minimum of four countries should be required to block any measure. Unfortunately, such an added condition would serve to make the new voting system almost as difficult to understand as the complex system of weighted votes it is to replace.
Among the most unpopular elements in the draft treaty was a proposal to limit the size of the European Commission to 15, with the other 10 countries being represented by non-voting commissioners without portfolios. Most small countries, particularly among the new member-states, want to retain the right of each country to nominate a commissioner.
The Irish Presidency is considering a compromise that would allow each country to nominate a commissioner for the time being but would commit leaders to review the position in a few years with a view to reducing the Commission's size.
Among the other issues to be resolved are Britain and Ireland's objection to abolishing the national veto in some areas of tax policy and criminal law. Britain has indicated that it is ready to drop its objection to introducing qualified majority voting on criminal law issues and Ireland is likely to follow suit, in return for a guarantee that any measure that fundamentally affects the common law system could be referred to EU leaders, who make decisions unanimously.
Britain and Ireland would find it much more difficult to concede on tax policy, although the draft treaty only proposes qualified majority voting on a limited number of issues such as measures to combat cross-border tax fraud.
In all EU negotiations, a concession to one government risks antagonising others and the Taoiseach will need to use considerable tact and subtlety to ensure that all 25 governments can claim victory after a final text is agreed.
If the leaders do reach agreement, each country will have two years to ratify the new treaty, some in parliament and others through referendums. If the EU agrees a constitutional treaty this year, it will not come into effect until 2006 - if at all.