[RalfDweflywex]

As you're aware, the populations of Canada and Australia are much than the UK's. However, as you note, they have a lot of natural resources. By contrast, a main driver of Britain's economy is financial services, and its world-wide market share in that segment will shrink dramatically.

The financial sector in the UK accounts for less than 10% of GDP, and doesn't just include banking, it also includes areas such as insurance and commodity trading. Furthermore the vast majority of banks in the city are foreign owned. UK industries such as Pharma and biotechs, IT, Defence Manufacturing, Aviation, Construction, Electronics and the Business Service sector are all strong, whilst service industries such as tourism and entertainment, and the education and knowlege sector are also very strong UK Industries. There is also no reason to believe that the UK Financial Centre is going to shrink dramaticaly, London is a world leader in professionalism in this field and has been a respected centre for many hundreds of years.

British Companies such as Glaxo SmithKline, British Airways, BAe, HSBC, Vodafone Group, TESCO etc to name but a few are some of the most respected and dominant companies in their fields. Vodafone even own a large slice of US Telecommunications company Verizon.