Britain would be richer if it was outside the European Union because it is a net-contributor to the EU budget...

This is untrue. We would be worse off out of Europe. An independent report published by the National Institute for Economic and Social Research in February 2000 showed that the British economy would contract (and taxes would rise) if we left the EU, despite the fact that the UK is a slight net contributor to the EU budget. David Mackie, Chief European Economist at JP Morgan has said: "In the great scheme of things, our net contributions are so small as to be trivial. There is no doubt in my mind that the net benefit of membership of the EU is many orders of magnitude above our net contribution to the EU budget.

For more myth-busting, have a look at the Euromyth section on Lib Dem MEP, Catherine Bearder's website.