. ▁After ▁the ▁refuse ▁of ▁Pierre ▁V ians son - P ont é ▁for ▁becoming ▁the ▁editor - in - ch ief ▁in ▁October ▁ 1 9 7 6 , ▁he ▁became ▁the ▁editor - in - ch ief ▁of ▁the ▁daily ▁newspaper ▁Le ▁Mat in ▁de ▁Paris . ▁He ▁then ▁left ▁the ▁Social ist ▁Party ▁the ▁same ▁year ▁to ▁eng age ▁his ▁support ▁for ▁the ▁Union ▁of ▁the ▁Left , ▁and ▁after ▁its ▁failure ▁in ▁September ▁ 1 9 7 7 , ▁for ▁the ▁Social ist ▁Party . ▁In ▁the ▁meant ime , ▁he ▁was ▁in ▁charge ▁of ▁the ▁economic ▁supp lement ▁and ▁editor - in - ch ief ▁of ▁the ▁week ly ▁economic ▁newspaper ▁La ▁Pres se ▁économ ique ▁( 1 9 7 9 – 8 0 ). ▁But ▁in ▁September ▁ 1 9 8 0 , ▁he ▁was ▁in ▁conflict ▁with ▁Claude ▁P erd riel , ▁whom ▁the ▁author itar ian ism , ▁om n ip ot ence ▁and ▁inter vention ism ▁in ▁his ▁re da ction al ▁activity ▁consider ably ▁reduced ▁his ▁authority . ▁He ▁then ▁became ▁editor - in - ch ief ▁of ▁the ▁economic ▁supp lement , ▁where ▁he ▁collabor ates ▁with ▁journalist ▁Pierre ▁L arg ue , ▁who ▁served ▁as ▁a ▁sh if ter ▁between ▁François - Hen ri ▁de ▁Vir ieu ▁and ▁the ▁typ ographic ▁workers . ▁ ▁Pres enter ▁of ▁L ' He ure ▁de ▁vérit é ▁ ▁Since ▁August ▁ 1 9 8 1 , ▁he ▁decided ▁to ▁join ▁An ten ne ▁