The supermarket chain has worked with Oscar-winning director Kevin Macdonald over the past 14 months on the 'Christmas in a Day' film, which will be released on YouTube on 29 November after a premiere at BAFTA.
It consists of clips submitted by the public, including a man who uses a spreadsheet to time his Christmas lunch to perfection, a very excited toddler and Pitcher, who asks whether Mary had to give birth in a stable because Jesus was conceived and born out of wedlock.
TV ads will act as a trailer for the film, starting tonight with a three-and-a-half-minute version taking the whole of the centre ad break during Coronation Street on ITV1.
The crowdsourced approach marks a change for the retailer, which hopes the ads will show how well it understands its customers.
Sainsbury's PR agency Blue Rubicon organised the campaign’s unveiling to journalists last Friday, an event attended by Sainsbury’s comms director Alex Cole and head of brand comms Mark Given.
UPDATE 29 NOVEMBER: The full film has been posted online and can be watched below.