Removing subsidies from tax havens

Letter in the Guardian, 7 June 2013:

The precise constitutional relationship between the UK and the overseas territories may be a matter of dispute, but what is indisputable is that the UK is guaranteeing the banks in these tax havens. Currently Jersey et al pretend they have viable financial sectors, yet they rely on the security of the very country whose tax take they are reducing. All Cameron has to do to is withdraw this support and no one will risk using banks based there.

Sadly, the Guardian chose to cut “Currently Jersey et al pretend they have viable financial sectors” from the letter.   I’d be interested in any evidence that contradicts this assertion.