The Big Bang took place in 1986. Thatcher was not overthrown until 1990. Brown's formalisation of deregulation with the FSA took place against a background of intensive and frenetic lobbying by bankers for less regulation (and howls of cuntservatives to the same effect).

The death of sensible banking was not because of Gordon Brown but because he was not strong enough to resist the conspiracy against the public interest rooted in capitalism (and the Greenspan theory).