About 10% of the UK's economic performance is not taxed, so £150bn is being lost to the Government....................staggering numbers, will anything be done?.
A big part of that is illegal activity, notably drug dealing and semi-legal/regulated activity such as prostitution and gambling. Calculation of our GDP has just been adjusted to take some of these into account
http://www.theguardian.com/business...ng-drugs-prostitution-uk-economy-gdp-eu-rules
It would be a bold government to fully legalise prostitution and drug supply, although it would bring in a hefty income (and save billions in policing/court/prison costs)