The Greek State issued an international invitation to tender for the planning, construction, self-financing and operation of the Thessaloniki underground railway. On conclusion of the phase for preselecting candidates, eight consortia, including Makedoniko Metro and the Thessaloniki Metro consortium, were authorised to submit tenders. The contract notices stated that a preselected consortium could be enlarged by the addition of new members during the pre-tender stage, but only up to the deadline for submission of tenders. After the second stage of procedure the composition of Makedoniko Metro proceeded to change again. Having departed substantially from the requirements laid down for the contract, the Ministry for the Environment, Regional Development and Public Works terminated the negotiations between the Greek State and Makedoniko Metro and invited the competing tenderer Thessaloniki Metro to enter into negotiations with it. The Administrative Court of Appeal in an action by Makedoniko Metro for compensation for damage suffered pursuant to the Ministry's decision, has referred a question to the Court of Justice for a preliminary ruling.The main question for the Court is whether national rules prohibiting a change, after submission of tenders, in the composition of a consortium taking part in the procedure for the award of a public works contract are permissible under the 1993 directive on the co-ordination of procedures for the award of public works contracts. In answer to the question put forward to it by the Greek court, the Court ruled that a national law may prohibit a change in the composition of a consortium after submission of tenders. The effective and rapid review procedures prescribed by Community law must be available to a consortium which has been excluded from the award procedure