I think we can renegotiate. Give and take.
Personally I like what EU proposing on financial transaction tax per every trade made by investment banks. This can be a minuscule amount but considering the zillions of transactions will come to good sum of money.
If EU and UK play a standard game I do believe other countries will follow.
If you want to conduct business in one of the most financially rich and busy regions on the globe one pays a small charge.
Banks caused this crash in taking excessive risk and so they should pay. Alternatively, all the profit they make goes to paying stupid daft bonuses on salaries not deserved to fat cats. These people are unhinged from rest of society and think the sun shines out of their rear.
In exchange for playing ball with EU in standardising financial tax we in return will get something back.
The UK is heavily reliant on the financial sector and we need to balance this with agriculture and manufacturing. These are also strategic industries where we should aim to have some presence.
These strategic and structural changes will benefit the whole country and not just London or the South.