Ross Kemp will reprise his role as EastEnders hardman Grant Mitchell in a heartbreaking family reunion to say goodbye to on-screen mother Peggy.
The actor, who last appeared regularly in the soap in 1999, will make a "brief return" to coincide with Dame Barbara Windsor's final scenes where her character will pass away from cancer.
Kemp said: "When I was approached about returning to EastEnders for Barbara's final episodes, it was something I could not turn down.
"Barbara is a very close friend, so when I learned of the storyline it felt right that the Mitchell brothers are reunited with their mother for the last time.
"I am really looking forward to going back to EastEnders and filming what are set to be some classic EastEnders episodes."
Mitchell matriarch Peggy made a surprise return to the soap on January 15 to inform son Phil (Steve McFadden) that her cancer had returned.
She is not scheduled to appear again until her final episodes in late spring, when Kemp will also return.
Grant first arrived in the Square in 1990 alongside brother Phil and has been involved in some of the soap's classic storylines, including his marriage to Tiffany (Martine McCutcheon) and her death, and various run-ins with his brother.
His return is likely to cause drama in Walford as Albert Square now plays residence to Grant's ex-wife Sharon ( Letitia Dean), currently married to his brother Phil, and Phil's ex-wife Kathy (Gillian Taylforth), who had an affair with Grant.
EastEnders executive producer Dominic Treadwell Collins said Kemp's return had been "at the top of my wish list".
He said: "Grant Mitchell is an EastEnders legend and finally he is returning home to Walford to say goodbye to his mother and be reunited not just with his old loves but also his brother.
"To have the Mitchell brothers come face to face again, having to face losing their mother, is an opportunity to show Ross Kemp and Steve McFadden at their very best.
"We are all so excited finally to have Ross back on the Square - and to have Ross Kemp, Barbara Windsor, Steve McFadden, Letitia Dean and Gillian Taylforth all on screen together at the same time as Peggy makes an exit like no other, this promises to be something very special."
The Mitchells are involved in another big storyline at the moment as Phil struggles to control his alcoholism.