EU:European Union leaders fly to Lisbon on Thursday to sign a treaty that most describe as essential to modernise the bloc's institutions after its enlargement in May 2004 from 15 countries to 27.
Yet according to a report by one of Europe's leading academic experts on the EU, the main institutions - the Council of Ministers, European Commission, European Parliament and European Court of Justice - are functioning as well as ever and the much-predicted gridlock has not happened.
"Established working methods and practices have survived the arrival of new member states," says Helen Wallace, a professor at the London School of Economics, who wrote the study. "The evidence of practice since May 2004 suggests that the EU's institutional processes and practice have stood up rather robustly to the impact of enlargement."
While her report does not pass judgment on the EU's new treaty, its conclusions will appeal to critics who contend that the pragmatic case for institutional reform after enlargement was a cover for a more ambitious project of deeper integration among member states.
The treaty abolishes the system under which the bloc's presidency rotates among member states every six months. Instead, a president chosen by member states will serve a 2½-year term.
The treaty cuts the commission's size, increases the number of European parliamentarians, and creates a high representative for foreign policy who will also serve as a senior commissioner.
It changes the EU's voting procedures and, for the first time, gives national parliaments a voice in making EU laws.
According to Ms Wallace, the EU's expansion has not damaged its ability to adopt legislation, in spite of complicated rules that often require the assent of the European parliament.
Whereas only 34 per cent of decisions subject to these rules were reached at first reading in 2003, the proportion rose to 45 per cent in 2004 and 64 in 2005 before easing to 59 in 2006.
She ascribes the EU's record since 2004 partly to the "less is better" philosophy of José Manuel Barroso, the Commission president. Ms Wallace also notes that, since enlargement, about 90 per cent of EU acts have been reached by consensus rather than by formal votes.
At the European Court of Justice, there were 731 pending cases in 2006, down from 740 in 2005, 840 in 2004 and 974 in 2003. The average length for preliminary rulings fell to 19.8 months in 2006 from 24.1 in 2002.
Ms Wallace says it is too early to assess the impact of the entry of Bulgaria and Romania, but her data "indicate that the 'business as usual' picture is more convincing than the 'gridlock' picture as regards practice in and output from the EU institutions since May 2004".