Martin Sheen plays the president in The West Wing
Hit television drama The West Wing is to lose two of its creative forces - Aaron Sorkin, who created the show, and Thomas Schlamme, its main director.
The pair, who were both also executive producers, will leave at the end of the current series - but the show will continue without them.
Sorkin has recently emerged from highly publicised personal problems, having drugs charges dropped in December after completing a rehabilitation programme.
The show, which portrays the inner workings of the White House, is currently in its fourth series and won its third Emmy award in a row for best drama last year.
The remaining executive producer, John Wells, who also produces ER and Third Watch, will stay on to take sole control of the show.
The West Wing has won a total of 17 Emmy awards
In a statement, Sorkin said: "This has been the experience of any writer's dreams.
"I had the best job in showbusiness for four years and I'll never forget that."
The pair said they would remain "the two
biggest fans of The West Wing".
There had been reports of tension between Sorkin and the show's producer, Warner Bros.
The fourth series began on a critical and ratings low but has picked up, helped by a storyline involving Friends star Matthew Perry as a White House counsel.
The show has won a total of 14 Emmy Awards and achieved the rare feat of winning the prestigious Peabody Award twice.
Schlamme picked up two Emmys for his directing and also won two prizes from the Directors Guild of America.
NBC entertainment president Jeff Zucker and Warner TV president Peter Roth thanked Sorkin and Schlamme "for creating
one of the finest shows to ever air on television".
In January, NBC reached a deal with Warner Bros to keep making The West Wing for at least two more seasons.