"How much / what sort of financial experience is required?"
One year perm at a bank or a project in a bank as a consultant. Investment banking and FX experience is valued much more.
If you never worked in any financial institution(like for an insurer), then there is maybe 1% chance you're getting a contract in one.
For £800 that's 5-10 years of experience with majority of it with one of the big consultancies(IBM GBS, Accenture, Deloitte) and a few big financial projects. Granted that's an introduction rate, that can go up if you negotiate well.
