According to article 113 of the European Patent Convention (EPC),
The decisions of the European Patent Office (EPO) may only be based on grounds or evidence on which the parties concerned have had an opportunity to present their comments.
The European Patent Office (EPO) shall examine, and decide upon, the European patent application or the European patent only in the text submitted to it, or agreed, by the applicant or the proprietor of the patent.
Prepared by European Patent Registration and Consulting Services GmbH