1 9 9 9 , ▁Ly ons ▁was ▁a ▁member ▁of ▁the ▁' Comm ission ▁on ▁the ▁£ ▁Ster ling ', ▁established ▁by ▁the ▁Le ader ▁of ▁the ▁O pp osition ▁William ▁H ague . ▁He ▁and ▁Ruth ▁Le a ▁wrote ▁up ▁the ▁Commission ' s ▁find ings . ▁He ▁provided ▁economic ▁input ▁to ▁Prime ▁Minister ▁Gordon ▁Brown ' s ▁first ▁Business ▁Council ▁for ▁Britain , ▁ 2 0 0 7 – 0 8 . ▁ ▁On ▁ 1 1 ▁December ▁ 2 0 1 2 , ▁the ▁Mayor ▁of ▁London , ▁Bor is ▁Johnson , ▁announced ▁that ▁Ly ons ▁was ▁to ▁join ▁his ▁team ▁as ▁his ▁Chief ▁Econom ic ▁Ad vis er . ▁During ▁his ▁first ▁term , ▁Ly ons ▁had ▁been ▁a ▁member ▁of ▁Johnson ' s ▁inform al ▁panel ▁of ▁economic ▁and ▁business ▁advis ers , ▁speaking ▁at ▁a ▁number ▁of ▁events ▁at ▁City ▁Hall ▁on ▁London ' s ▁global ▁position ▁during ▁the ▁term ▁of ▁the ▁previous ▁Mayor , ▁Ken ▁Living stone . ▁He ▁began ▁the ▁role ▁a ▁month ▁later ▁in ▁January ▁ 2 0 1 3 ▁and ▁left ▁in ▁April ▁ 2 0 1 6 , ▁at ▁the ▁conclusion ▁of ▁the ▁Mayor ' s ▁term . ▁While ▁at ▁City ▁Hall ▁Ly ons ▁ ▁champion ed ▁the ▁London ▁living ▁w age , ▁co - cha ired , ▁with ▁Mun ira ▁Mir za , ▁the ▁London ▁Str ateg ic ▁M igration ▁Part ners hip ▁P anel , ▁represented ▁the ▁Mayor ▁on ▁the ▁Board ▁of ▁City UK ▁and ▁sat ▁as ▁a ▁member