Hi and welcome to Just Answer!You will not be subject of double taxation - double taxation is eliminated by the tax treaty between Canada and UK.
I may not say if that income is taxable in UK or not - that is a question to UK tax experts.However, if it is taxable - as a resident of Canada - you will claim a credit for foreign tax paid on your Canada tax return.
If you are filing a paper return, attach your completed Form T2209, Federal Foreign Tax Credits and documents that show the foreign taxes you paid. - http://www.cra-arc.gc.ca/E/pbg/tf/t2209/t2209-10e.pdf
Complete Form T2209, Federal Foreign Tax Credits and enter the amount from line 10 on line 405 of your Schedule 1.
Let me know if you need any help.