If you are Resident for tax purposes in Canada, you should report all world income to CRA.
By UK-Canada Tax Treaty, recurring pensions arising in the UK should be taxed only in the state where they are received, ie in Canada. In other words, the pension is tax exempt from HMRC, but fully taxable by CRA.
On the other hand, parties that receive taxable pension income in a UK account ( and thereby are assumed to be tax resident in the UK), cannot also be considered tax resident in Canada.
