4 9 ▁seats ▁and ▁PO ▁ 3 4 ▁of ▁the ▁ 1 0 0 ▁seats , ▁leaving ▁eight ▁other ▁parties ▁with ▁the ▁remaining ▁ 1 7 ▁seats . ▁The ▁S LD ▁won ▁no ▁seats ▁in ▁the ▁Senate . ▁ ▁Background ▁The ▁ 2 0 0 5 ▁Se jm ▁was ▁elected ▁by ▁proportional ▁representation ▁from ▁multi - member ▁constitu encies , ▁with ▁seats ▁divided ▁among ▁parties ▁which ▁gain ▁more ▁than ▁five ▁percent ▁of ▁the ▁votes ▁using ▁the ▁d ' H ond t ▁method . ▁On ▁the ▁other ▁hand , ▁the ▁Senate ▁is ▁elected ▁under ▁first - p ast - the - post ▁b loc ▁voting . ▁This ▁tends ▁to ▁cause ▁the ▁party ▁or ▁coal ition ▁which ▁wins ▁the ▁elections ▁to ▁have ▁a ▁larger ▁majority ▁in ▁the ▁Senate ▁than ▁in ▁the ▁Se jm . ▁ ▁In ▁the ▁ 2 0 0 1 ▁elections ▁the ▁S LD ▁and ▁UP ▁won ▁ 2 1 6 ▁of ▁the ▁ 4 6 0 ▁seats , ▁and ▁were ▁able ▁to ▁form ▁a ▁government ▁with ▁the ▁support ▁of ▁the ▁Polish ▁People ' s ▁Party ▁( PS L ). ▁The ▁former ▁r uling ▁party , ▁Sol id ar ity ▁Elect oral ▁Action ▁( A WS ) ▁based ▁on ▁the ▁Sol id ar ity ▁trade ▁union , ▁lost ▁all ▁its ▁seats . ▁In ▁its ▁place ▁several ▁new ▁right - wing ▁parties ▁emer ged , ▁such ▁as ▁the ▁PO ▁and ▁the ▁Pi S . ▁ ▁After ▁ 2 0 0 3 ▁a ▁variety ▁of ▁factors ▁combined ▁to ▁bring ▁about ▁a ▁collapse ▁of ▁support ▁for