0 0 2 ▁he ▁was ▁a ▁research ▁assistant ▁to ▁the ▁P DS ▁parliament ary ▁group . ▁ ▁B irk wald ▁was ▁the ▁first ▁direct ▁candidate ▁in ▁the ▁federal ▁election ▁in ▁ 1 9 9 4 ▁in ▁C ologne ' s ▁south west . ▁In ▁ 2 0 0 0 , ▁he ▁joined ▁the ▁P DS ▁as ▁a ▁direct ▁candidate ▁for ▁the ▁NR W ▁state ▁election ▁in ▁C ologne ▁and ▁on ▁the ▁state ▁list . ▁In ▁the ▁federal ▁elections ▁in ▁ 2 0 0 2 , ▁ 2 0 0 5 , ▁ 2 0 0 9 ▁and ▁ 2 0 1 3 ▁and ▁in ▁the ▁state ▁election ▁in ▁North ▁Rh ine - West phal ia ▁in ▁ 2 0 0 5 , ▁he ▁was ▁again ▁direct ▁candidate ▁of ▁the ▁P DS ▁and ▁the ▁Left ▁respectively ▁in ▁the ▁constitu ency ▁of ▁C ologne ▁II ▁and ▁the ▁district ▁constitu ency ▁C ologne ▁I . ▁ ▁At ▁the ▁mer ger ▁convention ▁of ▁the ▁party ▁Die ▁Lin ke ▁in ▁June ▁ 2 0 0 7 , ▁Matth ias ▁B irk wald ▁participated ▁as ▁a ▁delegate ▁of ▁the ▁Federal ▁Working ▁Group ▁on ▁Cit iz ens ' ▁Rights ▁and ▁Dem ocracy . ▁Within ▁the ▁Left , ▁B irk wald ▁has ▁joined ▁the ▁Social ist ▁Left . ▁He ▁acted ▁in ▁the ▁working ▁group ▁" For ▁a ▁modern ▁repr ession - free , ▁needs - cover ing ▁social ▁minimum ▁income ▁security " ▁and ▁is ▁committed ▁to ▁a ▁" sol id ary ▁minimum ▁p ension ", ▁whose ▁central ▁found ations ▁he ▁developed