I have to renew my passport abroad. I was told by a counselor officer at the embassy that I would have to surrender my citizenship card even if I apply in person at the embassy. I would prefer not to do this because of clear reasons - if it is lost I will be in a desperate situation without any ID and no possibility to restore it from abroad. Would be thankful for similar experience/suggestions.

Hi.
I don't know which country you are applying from. I looked through Passport Canada's info & didn't see any place where it states that you have to surrender your citizenship card. Yes, you might have to submit a copy of it, but not the original.
Anyway, all details for Canadian passport renewal are clearly given at their website - Passport Canada: Step by Step Guide for Canadians
Choose your option (whether you are a Canadian living in US/Bermudas or whether you are a Canadian living abroad in any other country) & follow the directions as given.
Good luck!

Thanks for the answer. I checked Passport Canada website. There are no requirements there to surrender any ID!