European Diary: After months spent ploughing their way through the turgid text of the Lisbon Treaty, many EU diplomats hoped for a welcome break from EU "institution-building".
But in Brussels work on building the European project rarely stops and with the ratification process now in full swing (Hungary, Slovenia, Malta and France have ratified the treaty), EU ambassadors are already mulling over the practicalities of how to implement the treaty.
Slovenia, the current holder of the EU presidency, issued a secret paper to member states' ambassadors last week outlining 33 points in the treaty that still need to be clarified.
Within days the paper was leaked, (Click here for full text), provoking an outcry from British Eurosceptics, who noted that the most sensitive points in the paper - those related to the setting up of an EU external action force, the powers of a new president of the European Council, and the creation of a new European public prosecutor - will be resolved between diplomats and not included in the text of the treaty that member states actually ratify.
"Once the treaty is ratified, there'll be no going back," warned Neil O'Brien, director of the Eurosceptic British think tank, Open Europe. "MPs would effectively be signing a blank cheque to the EU if they ratify this without a referendum."
To describe the treaty, which runs to an excruciating 271 pages when its annexes and protocols are included, as a "blank cheque" is disingenuous. But it is true that big questions remain over exactly what all the articles will mean when implemented.
Take for example the EU's new external action service. Article 13 of the treaty outlines the broad mandate of the service, which is intended to assist the new high representative of the EU for foreign affairs and security policy. The service will include civil servants and officials from member states and the EU, according to the text, but the specific detail on how the service will operate has not been explicitly spelled out in the treaty.
Will the external action service replace member states' bilateral embassies in certain parts of the world? Will it get quick access to the EU budget to pay for emergency operations? Will new EU embassies simply issue passports to European citizens living outside the Union or will they assume a more political role, for example pushing the EU's political agenda or issuing political asylum in sensitive situations?
These are some of the key questions that still need to be decided in talks later this year involving member states' EU ambassadors, the new high representative for foreign affairs, the European Parliament and the European Commission.
Some of these decisions will require the unanimous backing of EU states; others will require a qualified majority.
Supporters of the treaty point out that there is nothing new in this diplomatic tidying-up exercise, which is required every time a new EU treaty is introduced. Writing every specific change into the treaty text is impossible and, in any event, judges at the European Court of Justice (ECJ) often act as catalysts of change by reinterpreting the EU treaties - although their role in the field of foreign affairs will be limited in the reform treaty.
"Member states often take a big leap in the dark where treaties are concerned, hoping that things will work out," says Hugo Brady, analyst with the think tank, Centre for European Reform.
"People tend to think that once a treaty is signed all the politics and debates are over: but, in fact, nothing could be further from the truth, often they are just beginning."
One recent example of judicial activism was provided by the ECJ in 2005 when it ruled that existing treaties gave the European Commission the power to force EU states to impose criminal penalties for breaches of EU environmental law.
This decision prompted the EU executive to push for further powers to enforce criminal sanctions in other fields such as copyright infringement and employers who hire illegal migrants. Whether the treaties provide the necessary legal powers to extend the commission's power in the criminal law field to other areas may also be a decision for the ECJ judges.
Personalities also play a role in shaping political institutions. For example, one of the biggest questions raised by the Lisbon Treaty is: just how much power and influence will the new president of the European Council have? Will he or she simply chair the quarterly meetings of EU leaders and broker behind-the-scenes deals on sensitive political issues? Or will the president become Europe's powerful new political figurehead in the world and shape the bloc's emerging foreign and security policy?
EU ambassadors will decide some of the parameters of the job - including the salary and compensation package - later this year, but the first person to take up the position will also play a key part in defining the role. Tony Blair is reportedly interested in the job if it has real power, and such an activist president would undoubtedly push the political boundaries of the job.
A potential rival, Luxembourg's Jean-Claude Juncker, would probably be more of a backroom facilitator, restricting the public profile of the new presidential role.
In other words, the text of the new treaty provides only the broad outline for how the EU will develop in coming years. But member states, MEPs, European commissioners, the new president of the council and the judges at the ECJ will fill in the political gaps.