The Czech constitutional court on Tuesday adjourned a hearing on whether the Lisbon treaty violates the constitution until November 3, meaning that this week’s key European Union summit will have to take place with the treaty still unratified by the Czech Republic.

The closely followed court case has been brought by a group of rebel senators who charge that the treaty undercuts Czech sovereignty by handing too much power to Brussels. Their action has provided Vaclav Klaus, the Czech president, with a reason not to sign the treaty, which has already been ratified by the Czech parliament and has been accepted by the rest of the EU.