(1) Where, at any time during an investigation under this Part, the competent authority suspects that there is a risk that, by virtue of conduct which may give rise to an infringement of relevant competition law, an undertaking or association of undertakings will cause serious and irreparable harm to competition, the competent authority may issue a notice in writing to the undertaking, or association of undertakings, concerned (in this Act referred to as a 'prohibition notice').

(2) A prohibition notice -

(a) shall state that the competent authority suspects that there is a risk that a notified undertaking will cause serious and irreparable harm to competition,

(b) shall state the reasons for that suspicion,

(c) shall specify the nature of the infringement of relevant competition law that the competent authority suspects has occurred or may be occurring,