Alright so short answer to this, no. The "alt-left" is largely a phantasm made up by the tabloids in the any case (the closest political tendency I could think of would be the younger set of tankies around stuff like Red London), but Lexit voters have totally different motivations in comparison to John Bull rightists, [edit-->] eg. concerns with the capture of the overwhelming part of the EU's institutions by neoliberal interests and associated fallout (such as
Viking-Laval, or enforced privatisation policies), or a forthright analysis of the way the EU acts to enable what amounts to an abusive relationships between powerful northern European states and weaker southern ones (most notably Greece).
Some even have specifically anti-racist reasons linked to the militarisation and attempted consolidation of "Fortress Europe", which Butchers alluded to when he pulled up that piece about the borders between Spain and Africa.