I am currently going through the "joy" of renewing my Canadian Passport. Unlike the pampered Brits who get 10 years of use out of their passports, Canadians have to go through this every five years.
The passports gods have decided to add a couple new hoops to the process, including two referees and additional documentation. The guarantor must be providing his services free of charge, which means that your GP are out of the question (since they charge for everything)
Finally, there is the pain of trying to find a photographer who meets the criteria of the Canadian Passport Authorities (no photo booths allowed). Size requirmentsand the elusive stamp on the back with photographer's address and space for the guarantor's signature.
Thankfully, I found folks in Glasgow who do this - Venart Photography on Bath Street in Glasgow. So I have an appointment to get this done. Then it is just the Guarantor and getting the documentation together for mailing to London.