One panellist said the campaign would "undoubtedly divide the room", while another said it was "a beautiful expression of Christmas".
The campaign centres around a catchy Christmas tune written by rapping comedian Doc Brown, with members of the public, Sainsbury's staff, and a handful of celebrities singing about Christmas traditions.
It has been viewed more than 300,000 times on Sainsbury's Facebook page (see end of article) since launching yesterday evening (12 November), and has been watched more than 200,000 additional times on YouTube.
According to social media monitoring tool Brandwatch, the campaign was mentioned 1,550 times across social media between yesterday and 10am today. The audience online was 60 per cent female, while 63 per cent of mentions have been positive and 37 per cent have been negative.
But what did the PRWeek Christmas panel think?
James Herring, managing partner at Taylor Herring, said: "This song is undoubtedly going to divide the room - but this ad wins the supermarket sweep for me so far. Big on laughs, nostalgia and festive emotion. Add Pharrell's 'Happy' directors, Ricky Tomlinson and Kermit the Frog, how could you possibly fail?"
Nik Govier, co-founder of Unity, said: "Love this. I like that they've committed so fully to 'Living Well' – which they started back in January – with its distinct black, white and orange colour pallet that instantly says 'Sainsbury's'. It also doesn't feel like it's trying too hard. It's just a beautiful expression of Christmas that everyone can relate to. But most of all, I like that it feels different from the rest.
"I get the feeling that everyone else planned their ads with other retailers' potential campaigns in mind. But with this ad it just feels like they asked 'what's right for us?' and have truly gone for it."
David Fraser, founder of Ready10, said: "Using 'Marmite' as a noun has become overused and tired, but it's probably the best way to describe this Sainsbury's spot. People will either love it or hate it and a quick scroll through social media last night confirmed that. I have to confess that I loved every bit of this. It's unpretentious and real. My only complaint is the presence of Kermit and Ricky Tomlinson. It doesn't need them and it's almost like Sainsbury's didn't quite trust themselves enough to not use a celebrity in the spot somewhere."
Fraser added: "If we're looking for a festive ad winner, I am finding it tough to call between M&S and Sainsbury's."