Ratificatie Verdrag van Lissabon mogelijk vertraagd door Duitsland (en)
Formal ratification of the EU treaty in Germany may be delayed, meaning the bloc's biggest member state would not sign off the treaty in time for it to come into force across all member states at the beginning of 2009 as planned.
According to a report in German daily Die Welt, politicians from the Left Party as well as Peter Gauweiler, a centre-right politician from one of governing parties -the CSU - are examining the text of the EU treaty to see if they can bring a case before the country's constitutional court.
Their move could mean that the final formal step of ratification is delayed.
German MPs are widely expected to approve the treaty when it comes before parliament in May.
However, the text then needs to be signed off by the country's president, Horst Kohler.
If Mr Gauweiler has put a case before the court, Mr Kohler will then have to decide whether to go ahead and sign off the treaty anyway or wait for the court to make its case.
There has already been a precedent for this. In June 2005, Mr Kohler refused to sign off the German law approving the original EU constitution. In addition to France and the Netherlands having rejected the document, Mr Gauweiler had also brought a case against the EU constitution before Germany's constitutional court.
At the time, the constitutional judge in charge of the issue, Siegfried Bross, advised Mr Kohler to wait until the court's decision before signing off the EU document, notes Die Welt.
Mr Gauweiler had complained that the EU constitution took too much power away from the country's national parliament, arguing that the document overstepped the boundaries that the German constitution provides for the integration of state institutions in the EU.
Mr Kohler, who hopes to be re-elected as president in May 2009, now finds himself in an awkward position.
Formally, it is possible to sign off the treaty even if the court is examining it, but such a move is politically difficult, especially if the constitutional court were to eventually decide against the legality of the EU document.
So far Hungary, France, Slovenia, Malta and Romania have ratified the text, which needs to be approved by all EU member states for it to come into force.
A delay in ratification by Germany would be embarrassing for chancellor Angela Merkel, who was largely responsible for getting a new treaty into shape again following the rejected constitution.