I'm not going to do any countries I know nothing about other than from their Wikipedia page
Australia:
GreensAustria:
Die GrünenBelgium:
Groen/EcoloBolivia:
MASBrazil:
PTCanada:
NDPDenmark:
Socialist People's Party, maybe
Social Liberal PartyFinland:
Green LeagueFrance:
EELVGermany:
Die GrünenGreece:
DIMARIceland:
Social Democratic AllianceIndia:
INC, very reluctantly, only because all the other parties suck
Ireland:
LabourIsrael:
MeretzItaly:
SELJapan:
DPJ, most likely, maybe
SDPMexico:
PRDNetherlands:
PvdA/
GroenLinks swing voter
New Zealand:
GreensNorway:
ArbeiderpartietPoland:
Palikot MovementScotland:
SNPSouth Africa: They all suck
South Korea:
UPPSpain:
PSOE in the past,
PSOE/
IU/
UPyD swing voter now
Sweden:
Social Democratic Party/
Greens swing voter
Switzerland:
Green PartyTaiwan:
DPPTurkey:
CHP, somewhat hesitantly
UK: Previously
Labour/
Lib Dem swing voter, now
Labour