4If after the publication of the notice with respect to any draft regulations (whether an original or amended draft) any general objection (as defined in paragraph 6 of this Schedule) is made within the required time with respect to the draft and not withdrawn, then, unless a previous inquiry under this Schedule has been held with respect to the draft or some previous draft of the regulations, he shall before making the regulations direct an inquiry to be held in the manner hereinafter provided and he may, if he thinks fit, also direct such an inquiry to be held in regard to any objection, notwithstanding that no such general objection has been made or that such a previous inquiry has been held as aforesaid.