Airbus 318/319/320/321 Undifferentiated
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
General Flight Cancelled / Delayed; General Maintenance Action; General Work Refused
Aircraft
Airplane was towed to gate. After the safety inspection was completed we were allowed to board. The entire cabin and flight deck smelled like fish. The APU; air conditioning packs and APU bleed were on. The cargo bins smelled normally. The smell was so intense that the entire flight crew had to deplane after a short stay on board. After reporting the issue to the Gate Agent; Dispatch and the ZZZ Chief Pilot; we were given a tail swap to operate flight from ZZZ to ZZZ1. [Aircraft] was then assigned to a different flight crew. I recommend that the airplane be sufficiently cleaned before being assigned to another crew after we reported the problem.
Airbus First Officer reported strong odor of fish during preflight resulting in an aircraft swap.