The campaign, created by Abbott Mead Vickers BBDO, surrounds the treatment of broiler chickens, focusing on how quickly the animals are reared for their meat compared with hens reared for egg laying.
The RSPCA said the Broadcast Advertising Clearance Centre had rejected the ads twice, even after the charity re-edited the film following comments made by the watchdog. Emma Nutbrown, an RSPCA spokeswoman, denied that the ad was trying to change legislation, which was the criticism raised by Bacc's of the commercial.
"The campaign is an educational campaign, and it poses a question at the end so viewers are free to make up their own minds," she said.
The ad, which launches today, will now go ahead and run in cinemas, backed up by a print campaign in national newspapers.
The RSPCA says the chickens reared for their meat can suffer sudden heart failure, leg pain and ammonia burns before they are slaughtered aged six weeks, and says it is one of the most pressing animal welfare issues in the UK today.
Its "Suffering in Silence" campaign aims to raise awareness among consumers, and get them to pressure supermarkets to force suppliers to improve conditions.
If you have an opinion on this or any other issue raised on Brand Republic, join the debate in the .