For those that aren't going to click the link: he was a Conservative initially before becoming an independent and he had radical policies to reduce unemployment that weren't popular in the then laissez-faire Labour party (or Conservatives really) such as tariffs to protect British industries from 'international finance', state nationalisation of main industries, and plans for a corporate state by merging businesses, workers, and the government into one. He was also against free trade being noted as saying he was trying to challenge the '50-year-old system of free trade which exposes industry in the home market to the chaos of world conditions, such as price fluctuation, dumping, and the competition of sweated labour'.
After the split from Labour and failing to see success in his own New Party he went on a study tour of Italy and it's here you see the sharp turn towards the right wing and the formation of the BUP which was obviously authoritarian corporate fascism, strongly anti-Communist, and frequently clashed with Jewish groups.
As dragonwriter notes in his posts in this thread, corporatism is something that's sometimes shared among these ideologies but the gulf between those ideologies can still be pretty large, authoritarian nationalism inherently excludes certain groups in societies and is worlds apart from some other forms of socialism even if the goal of both is to end or reduce class conflict.