City of London
The mother of a global tax haven network
Margaret Thatcher at the London Stock Exchange, 1 February 1979
Big Bang became one of the cornerstones of Margaret Thatcher government's reform programme. Prior to these reforms, the once-dominant financial institutions of the City of London were failing to compete with foreign banking. While London was still a global centre of finance, it had been surpassed by New York, and was in danger of falling still further behind. Thatcher's government claimed that ... the solution lay in the free market doctrines of unfettered competition and meritocracy. The effects of Big Bang were dramatic, with London's place as a financial capital decisively strengthened, to the point where it is arguably the world's most important financial centre even to the present day.
London retains its place at the top of the comprehensive ranking from last year and further increases its score to widen the gap with New York at No. 2.
The City of London dragon at Temple Bar
Over and over again we have seen that there is in this country another power than that which has its seat at Westminster. The City of London, a convenient term for a collection of financial interests, is able to assert itself against the Government of the country. Those who control money can pursue a policy at home and abroad contrary to that which has been decided by the people. The first step in the transfer of this power is the conversion of the Bank of England into a state institution. (quoted from Nicholas Shaxson - Treasure Islands: Tax Havens and the Men who Stole the World)
Cameron could act to bring UK territories into line on offshore investments but he's in thrall to powerful City players.
If Britain's network were assessed together, it would be at the top.