The much-disputed text has been carefully prepared by the German Presidency following secret consultations with EU member states and institutions.
Just days ahead of the declaration, Czech President Vaclav Klaus had criticised the "untransparent" method of drafting the text.
One of the main sticking points, the mention of the Constitutional Treaty as an outlook, was finally dropped, due to fierce opposition from member states such as the UK and Poland. Instead, it is likely only to refer to "a treaty" or more generally "institutional reform".
Other disputed issues were whether to mention the euro and enlargement as EU achievements. The UK in the end did not oppose a reference to the euro, despite the fact that not all member states participate in the common currency.
The EU member state's view on enlargement and especially future enlargement diverge substantially. Some countries such as the UK support further enlargement, while for others this is a major concern, especially in France and the Netherlands, where enlargement played a role in the rejection of the Constitutional Treaty.
The text will also make no mention of the EU's Judaeo-Christian roots, as this would have been unacceptable to member states with a strong secular tradition, such as France.
According to Commission sources, there will be a reference to 2009 as a target deadline for institutional reform, without specifically mentioning what form this may take. The German Presidency has underlined that the EU should have a new treaty agreed and ratified before the European elections in 2009.
The declaration is to be signed by the presidents of the Council, the Parliament and the Commission. However, some sources indicated that not all EU leaders were ready to put their signature to the text.
Moreover, German Chancellor Angela Merkel is expected to communicate her personal aspirations for the German Presidency, which aims to bring the stalled Constitutional Treaty back on track.
