 According to Czech Constitution, the treaty cannot be ratified until a ruling of the Constitutional Court is delivered.Beside the constitutional challenge president Klaus, notwithstanding Czech parliament approval of the treaty, asked for an opt-out from the Charter of Fundamental Rights of the European Union.He said that, were the charter to gain full legal strength, it would jeopardise the Beneš decrees, and in particular the decree that confiscated, without giving compensation, the properties of Germans and Hungarians during the Second World War.