sentences:  The Crosby by-election took place against an almost unprecedented backdrop of division and disunity within both the Conservative and Labour parties, combined with social unrest and economic recession in the United Kingdom as a whole.The opposition Labour Party was riven by factionalism and divided over entryism - in particular, that of the Militant tendency.It expounded left-wing policies, with perceived weak leadership provided by Michael Foot, who was routinely ridiculed by the national press.