NewDawn wrote:
I don't know about Canada, but for the UK, EU laws apply (usually). It's a difficult question to answer. Immigration from a non EU country into the EU isn't easy, and it may be even more difficult if you need services. On the other hand, I'm positive there is an anti-discrimination law that protects people with an ASD diagnosis. Your best option is to contact the UK embassy. They can inform you in detail what is possible and which criteria you must meet. I'm pretty sure that having a job or other means of income in the UK is one of them.
If you're outside the EU and you want to do it legally and honestly, it will often not be easy for you.
If you have a passport from an EU country or can obtain one, you can just walk in to Britain.