LONDON (Reuters) – The co-founder of a British neo-Nazi group, whose members have planned or praised the murder of lawmakers, was jailed on Tuesday for being a member of a banned organisation. Alex Davies, 28, helped to set up National Action, a white supremacist group which was proscribed by the government in 2016, after it openly celebrated the killing of Jo Cox, a member of parliament. She was shot and stabbed to death by a Nazi-obsessed recluse in a frenzied street attack. Davies was found guilty last month of remaining a member of the group after it was banned. He was jailed for eight-and…