Greece has received a reasoned opinion from the European Commission alleging breach of the procurement rules in relation to a tender for the supply of underground electricity cables for a public utility. During an open tender procedure and following the submission of final offers, one bidder unilaterally offered to discount its initial offer and was offered the contract at a new, lower price. The Commission has said that modifying a legally binding offer in this manner is against the rules of an open procedure because other bidders were precluded from participating on an equal basis. Bidders must know what the applicable rules are advance and contracting authorities cannot make arbitrary changes to the procedures during the course of the procedure.