The more ties you have with Canada, the more likely CRA is to deem you a taxpayer. There is a host of ties -- such as a home in Canada, a spouse in Canada, personal property in Canada, bank accounts, a driver's licence, etc
You may be a non resident for immigration purposes but a tax resident for tax purposes. I think you need a lawyer.
Thanks for the info', I finally finished reading a big section of the CRA web site.
I think the key point here is that the UK and Canada have a tax treaty, so I cannot "in theory" be taxed twice.
I doubt that I need a lawyer, I will just send the information to CRA, it will cost less.
As I said I have no wish to avoid tax, if I am going to make a life in I Canada should expect to pay into the system.
Tax limitation is good, tax avoidance is illegal