Actress Elaine Lordan, who plays Lynne Slater in BBC One soap EastEnders, is to leave next summer after four years.
Elaine Lordan joined the show in September 2000
A BBC statement said the hit soap had to "keep itself fresh and it was felt it was time for Lynne to move on".
Lordan said she and executive producer Louise Berridge decided her contract should not be renewed when it expires.
The actress was convicted of drink driving in October and her drinking habits have been the subject of numerous reports in the tabloid press.
The BBC statement said: "Lynne Slater is to be written out of EastEnders next summer.
She was banned from driving for a year after drink driving
"Lynne has been a key figure in EastEnders in the last four years as a member of arguably the most successful family in soap.
"Elaine Lordan has made a tremendous contribution to the programme and we wish her the best of luck in the future."
Lordan said: "I've had a wonderful time on EastEnders and after a discussion with Louise Berridge, we decided not to renew my contract when it expires next year."