commiss decis juli amend decis eec set advisori committe open public procur eec commiss european commun regard treati establish european econom commun commiss decis eec set advisori committe open public procur task assist econom technic legal social aspect public procur number member constitut committe initi fix maximum provid articl abovement decis number member origin fix prove insuffici enabl committe carri task effect assess social dimens public procur ground enlarg decid articl articl decis eec replac text committe compris member articl decis effect juli brussel juli commiss cockfield vice presid oj