Pam's character was killed off on New Year's Day 2012 when she passed away from pancreatic cancer.
But Barbara, who soon will make a one-off return to 'EastEnders' as Peggy Mitchell to visit son Phil (Steve McFadden) in hospital, said her old pal Pam should never have been shown the door.
She told Inside Soap: "I think that Pat is sorely missed from EastEnders. Sorry to offend the people who made that decision, but it was a bad choice to kill her. Millions of other fans of the show feel that way, too."
Barbara said she still found time to keep up with her old Walford friends.
"Obviously, I see Steve a lot, and I also see and socialise with the magnificent June Brown (Dot Branning) and Pam St Clement. We like to go to the theatre and have dinner and a good old rabbit afterwards.
"June is an incredible lady and, when I was in the show, we would always lunch together. I adore her. As for Pam, my nights out with her are equally as enjoyable."