When Dave Nellist entered parliament in 1983 as the Labour MP for Coventry South East, he became one of Westminster’s best-known socialists.  He was seen as a workers’ MP on a worker’s wage, donating more than half his salary to left-wing causes.  But within a few years, he was embroiled in a bitter political dispute inside the Labour Party that ultimately led to his suspension and expulsion.  He was associated with the Marxist newspaper Militant and his support for the mass campaign of non-payment of the poll tax.  Now, more than 40 years later, one question remains unanswered: what did Britain’s…