Criminal and justice affairs:The Republic will join the UK in opting out of efforts to increase co-operation on criminal and justice issues if these are included in a new European Union treaty.
Under the original proposals, changes to the definition of crimes, the type of sentences they should attract, and the mutual recognition of court judgments, would be made by majority voting.
Equally, changes to passport rules, the handling of identity cards, residence permits and other official documents would also be decided by EU justice ministers by a majority vote.
British prime minister Tony Blair resisted the proposals, insisting that his opposition to them was one of his "four red lines" for the Brussels talks.
In deference to Mr Blair, the EU leaders agreed that changes to court rules for criminal cases included in any new treaty would allow some member states to stand aside.
The British government believed that the changes could undermine its common law system that it shares with Ireland, and this led to a compromise formula from the German EU presidency.
A new treaty would give Britain the ability to opt in to new EU justice proposals that it supports, but withdraw from new EU laws that it does agree to, as happened a decade ago with the Schengen passport rules.
Believing that it must follow the British lead, because of the existence of the common travel area and a similar legal system, Ireland will also be offered the compromise but will probably not make a decision whether to accept it until an intergovernmental conference in the autumn.
In cases where objecting member states believe that "fundamental aspects of its criminal justice system" are threatened, they will be able to insist that the issue goes back to the European Council.
Such an action will force the European Commission to suspend plans for legislation, until the European Council unanimously agrees that it can be put back on the agenda.
However, other member states, if they number more than a third of the total, who wish to go ahead and increase co-operation, will be so, following a four-month delay.