The Czech constitutional court adjourned a hearing on a legal challenge to the Lisbon Treaty today and said it would probably deliver a ruling next week.
The court's decision means the Czech Republic cannot complete ratification of the treaty before an EU summit on Thursday and Friday. This is because President Vaclav Klaus cannot sign the treaty before the court rules on the legal challenge, which was filed filed by senators who are his allies.
The decision also means EU leaders are now less likely than ever to agree at the summit this week on who should fill two posts that would be created under the treaty - a president of the Council of EU leaders and a foreign policy chief with enhanced powers. The leaders had said they needed legal clarity to agree on the appointments, but the court has not provided this.
"I expect some informal discussions on the top jobs, especially in the margins. But I don't see us having detailed discussions or certainly any decisions at the summit on these positions," a presidency official had said even before the court announcement.
Although EU leaders had hoped for clarity today, the court could have delayed its next sitting until a much later date, delaying implementation of the treaty even further.
Most political analysts expect the Czech court to reject the legal challenge and Mr Klaus to sign the treaty soon. EU leaders say they are optimistic about the outcome.
EU leaders are expected to focus at the summit on demands Klaus has made for an opt-out from a human rights charter that is attached to the treaty. They are expected to agree on the wording of a political declaration that would promise the Czechs an opt-out from the charter but would not require any changes to the treaty.
The wording could then be included in the next treaty the EU adopts after the Lisbon treaty, possibly when the EU next takes in a new member state. This is widely expected to be Croatia.
Such a deal would save face for Mr Klaus, who has long opposed the treaty, but would also be a relief to other EU leaders because it would remove the last obstacle to ratification.
Sweden, which holds the EU presidency and has been negotiating with the Czech government, could now face greater pressure to call a special summit on the new appointments because there will be no final decisions on the nominations at this week's summit.
Swedish officials said before the court's announcement today that they had not reached any agreement on holding an extra summit but did not rule out the possibility of doing so once the court reached a decision.