This evangelising of a wealth tax should have made for a truly amazing documentary. But it allows its host to be totally out-argued by all his interviewees. Why?

The trader-turned-campaigner argues that drastic steps need to be taken to close the UK's huge wealth gap

The former Citibank trader put his controversial plans to entrepreneurs, tax experts, wealthy estate owners and online finance gurus while filming his new Channel 4 programme 'How…