( 1 ) A common question of law and facts is involved in all these petitions and therefore all the petitions are considered together and decided by this common judgement.

( 2 ) THE petitioners herein are consumers of Gujarat Electricity Board. They are High Tension Consumers and they have been charged on the basis of tariff applicable to them as HT consumers. 2. 1 according to the petitioners, the respondent Board issued exhorbitant supplementary bills to the petitioners being differential amount due to revision of tariff on account of change of classification from HTP-I to HTP-II (A ). The petitioners were also informed that although original connection was released under HTP-I category, considering the activities carried out by the petitioners in their units, their units would fall under HTP-II (A) category. It appears that the new tariff was introduced with effect from 10. 10. 2000 and the special bill has been calculated on the basis of new tariff. Therefore, the petitioners herein have challenged the special bills issued to them, the action of arbitrarily changing the classification from HTP-I to HTP-II (A) and the demand of new tariff with retrospective effec