Germany has Die Linke, Spain has Podemos, Greece has Syriza, France has Front Gauche ect, nearly every Western European Country has some left of centre party active within its politics, obviously Britain is generally a more Conservative Country and FPTP hamstrings more extreme parties, I have a few ideas but I'm not sure how feasible they are.
1) A bigger Labour split over Iraq, leading to more anti-war MPs defecting George Galloway style.
2) Labour NEC forces Corbyn off the ballot in the 2016 leadership election, Corbyn leaves taking with him a handful of loyal MPs, and a large chunk of the membership, possibly forming a new party either alone or with the help of some more fringe parties like TUSC.
3) Labour shifts to the right much earlier causing a left wing gang of four in the 80s rather than a moderate one.
4) An entirely new grassroots movement pops up.
What are people's thoughts?