Join Date: Oct 2011
Location: Anywhere I need to be.
Programs: OW Emerald, *A Gold, NEXUS, GE, ABTC/APEC, South Korea SES, eIACS, PP, Hyatt Diamond
Posts: 16,046
In your scenario, could you not just use the Canadian passport in order to fly the journey (checkin, security in Canada, and assuming the length of stay in the UK is <6 months,) and enter the UK on the British passport
Similarly, when exiting the UK, you would again use the Canadian passport to check in and board using the Canadian passport.
(I already do something like this going to and from the PRC/HK, though for the former I must show Home Return Permit and HKPIC for the latter at check in.)