EastEnders actor John Bardon has been admitted to hospital following a suspected stroke.
John Bardon first joined EastEnders in 1996
The 67-year-old has played Jim Branning in the BBC One soap for 11 years, becoming a regular fixture in 1999.
EastEnders' executive producer Diederick Santer said: "I am saddened to hear John has been taken ill. My thoughts are with John and his family."
Bardon and June Brown, who plays his on-screen wife Dot, have twice won the British Soap Award for best couple.
The pair have recently been involved in a high-profile storyline involving an abandoned baby.
The actor recently took part in celebrity talent contest Just the Two of Us, where he was paired up with singer Jocelyn Brown.
Other acting credits include Minder and Rumpole of the Bailey, as well as appearing in the 1970s stage show of Dad's Army.