A united left movement does not exist and cannot exist, since the leftists by themselves are very diverse, and this diversity has an objective reason."Capitalism would not be capitalism if the "pure" proletariat were not surrounded by a large number of exceedingly motley types intermediate between the proletariat and the semi-proletarian ..., between the semi-proletarian ...and petty artisan, handicraft worker and small master in general..." wich ,as a rule,is a mass social base of the majority of leftist's organizations.That is, in short, the main reason is not in personal ambitions or in historical but in social-class differences. So a temporary tactical alliance is possible,but not the united leftist's organization.
Any anti-communist is a dog. - Jean-Paul Sartre.