According to economist James Henry financial assets held offshore round the world are worth “at least” $21tn and perhaps as much as $32tn.

(He calculated that £6.3trillion of these assets are owned by just 92,000 people – or 0.001 per cent of the world’s population. The international campaign group Tax Justice Network, which commissioned the research estimates that around $250billion is lost in taxes each year by governments worldwide as a result of the wealthiest individuals holding their assets offshore.)