Pauline Quirke had a furious war of words with Birds of a Feather co-star Lesley Joseph, reports say.
Pauline - who played Sharon Theodopolopodos in the 90s hit - left fans crestfallen when she didn't return alongside Linda Robson and Lesley Joseph for last year's Christmas special after she quit acting.
Now reports claim that a rift had formed within the cast - that culminated in a heated exchange at Teddington Studios.
A source told The Sun that Pauline and Lesley were "squaring off" against each other, before they were "basically pulled apart" by crew members.
"It's a sad ending to what was one of the most endearing and popular friendships in television," the source added.
"Linda doesn't believe they'll ever speak again."
The Mirror has contacted reps for Pauline, Lesley and Linda for comment, and all three declined to comment to The Sun.
When Linda shared the news that Birds of a Feather would be making a festive comeback last year, she was asked by the Loose Women panel if all three of the original leads would be returning.
But Linda told them: "Pauline didn't do it, she didn't want to this year, she wants to give up acting and she wants to carry on with her acting academy.
"We really missed her, but it's her choice."
Sharon's absence from the episode was explained as her being stuck on a cruise ship near Costa Rica.
The sitcom first aired in 1989, following Sharon and Linda's Tracey Stubbs, sisters who moved in together when both their husbands found themselves behind bars.
It ran for nine years on the BBC, before being picked up again by ITV down the line in 2014.
And despite Pauline's absence, the 2020 Christmas special proved a hit with viewers, raking in nearly 8 million viewers.
An ITV spokesperson said at the time: "Unfortunately, Pauline Quirke will not be taking part as she's stepping back from acting to focus on her 200 nationwide performing arts academies."