The axe will fall on Defence, Housing, Transport and Higher Education....

[Huguenot]

Trade regulations tend to work because of mutual benefits.

The challenge with finance is that it's both mobile and unevenly distributed. There are plenty of countries for whom NOT signing up to a global trading tax would have no downside, whereas attracting the finance industry has an upside.

Hence you'd struggle to get a treaty that was adhered to by all.