Article 4
1. The period referred to in Article 7 (1) (b) of Regulation (EEC) No 1422/78 shall be not more than five consecutive calendar months, for which the producer has received payment for milk sold to the MMB, and which occur within the 12 month period preceding the commencement date for withholding of milk from the MMB. The rights referred to in that Article may also be exercised if, during any period of 12 months, the average price paid to a producer for that period falls below the level referred to therein. 2. Producers wishing to exercise the right referred to in Article 7 (1) (b) of Regulation (EEC) No 1422/78 shall inform the competent authority and the MMB of their intention in writing at least one month before the start of withholding, stating the likely or precise period of withholding from the MMB, and whether all milk sold by the producer will be withheld or a proportion of the total sale. Where a proportion of milk sales by the producer is involved, the quantity of milk to be withheld shall be stated. The intention to withhold can be presented immediately upon receipt of the first of the payments referred to in paragraph 1. Without prejudice to earlier resumption of deliveries to the MMB, the period of withholding may not continue more than six months beyond a period of three consecutive months from which the MMB again pays a milk price in excess of the established equivalent of the intervention price level. 3. Any earlier resumption of deliveries to the MMB is conditional upon a two month advance notice of resumption to the MMB, unless a precise period of withholding was indicated in the information referred to in paragraph 2. 4. The United Kingdom: (a) shall adopt detailed provisions to enable the milk producer to determine the milk price resulting from the intervention prices applicable ; these provisions shall include the publication of an intervention price equivalent of milk established as a guide by an administrative authority, independent of the MMB, on the basis of average margins and conversion factors without prejudice to the intervention price equivalent of milk which can be established by the producer in relation to his or her individual circumstances; (b) may adopt detailed provisions to guarantee that the quantities of milk communicated in accordance with paragraph 2 are actually processed into butter or skimmed-milk powder with a view to sale to the intervention agency and that these products are in fact offered for sale to the intervention agency ; these provisions may include requirements that producers must keep and reveal to the competent authority contracts and other documents relating to that milk. Article 2 (2) and (3) shall apply by analogy to these detailed provisions.