Hi perdushka,
As you will be resident in Canada, you will be taxable on your world-wide income in Canada.
If you are a UK government employee, such as civil servant or serving military, you would remain taxable in the UK on this employment.
If you are in receipt of a UK government pension (not state pension) this will remain taxable in the UK.
If you will be renting out UK property while living in Canada, you would declare this income in a Self Assessment tax return each year, as the UK has the right to tax UK property income.
Have a look at:
Check if you need to send a Self Assessment tax return
Thank you.