Speaking at Zagreb's Faculty of Political Sciences about the role of the European Parliament in the process of EU enlargement, Priestly said that the European Union needed a constitution in order to be able to function more efficiently in the future.
Europe needs a constitution and a vast majority of deputies in the European Parliament support it, Priestly said.
The 25-member EU is currently operating according to the rules laid down in the Nice Treaty, which was designed for 27 member states, the quota to be filled with the admission of Bulgaria and Romania. The Nice Treaty was to be replaced with the European Constitution, but its ratification got stuck after it was rejected in referendums in France and the Netherlands.
The EU Constitution was rejected for a number of reasons, the main ones being fear of globalisation and further EU expansion, notably to the large and mostly Muslim-populated Turkey, and citizens' dissatisfaction with national governments, Priestly said.
The EU constitutional crisis should not slow down Croatia's admission to the EU, Priestly said.
The majority in the European Parliament believes that we should define the EU's internal structure on our own and that Croatia should not be held hostage to that problem, the European Parliament official said.
European leaders are expected to make a decision on future measures regarding the EU Constitution by the end of 2008, by which time Croatia plans to complete its accession talks.
Croatia will earn the right to full EU membership if it continues to implement reforms, Priestly said, adding that the country had to complete economic reforms, reform the state administration and the judiciary, and continue full cooperation with the Hague war crimes tribunal.