When you pay tax and NI throughout your working life in the UK, you have entered into a contract with the government that in return for your contributions you will receive a state pension. Why should the state then be able to dictate where you should live?
I do pay tax at source on my two UK government pensions Teachers and Civil Service) but at the moment my state retirement pension is taxed by the French government. This holds for all EU countries. Non-British EU pensioners living in Britain will pay UK tax on their state retirement pension but any pensions they have by virtue of employment by a member state will be taxed at source. This is a reciprocal agreement. What we are asking for is that Britain enters into a reciprocal agreement with Commonwealth countries.
Not everybody moved abroad just to get a better life, but even if we do, is there not a smidgen of envy in some people's attitude? I can assure you that emigrants often face just the same problems as people who remain in Britain and they have to pay for food, housing, health, fuel,insurance, etc. etc. If they remain on a frozen pension for ten years or more, how is it suggested that they support themselves?
A friend of mine had to move to Australia because her daughter developed MS and could not cope with her three young children - should she be penalised for going out to help?