Competent authorities are thereforeobliged to comply with the procedures and requirements specified in Article 6 of the Directive, whether or not they are also bound by other obligations.Accordingly no competent authoritymay agree to a plan or project unless it has ascertained that (a) the plan or projectwill have no significant effect on a European site, or that (b) the integrity of the site will not be adversely affected, or that (c) site integrity will be adverselyaffected but that there is no alternative solution and the plan or project mustbe carried out for imperative...