Political intrigue suspected as man who created 'West Wing' resigns

The West Wing, American television's fly-on-the-wall look at the drama of running the most powerful country in the world, looked unlikely to survive much beyond its first four-year term yesterday after the series' creator and writer, Aaron Sorkin, said he was quitting.

Mr Sorkin has written just about every word of every script since the show began back in the Clinton era, raising questions about who exactly might be able to replace him. His departure, and that of the programme's director and executive producer, Thomas Schlamme, follows a season of falling ratings, cost overruns and some unwelcome heat about the suitability of the fictional President Josiah Bartlet's liberal politics at a time when the real-life White House is one of the most right-wing ever.

Mr Sorkin's parting statement was upbeat, describing The West Wing as "the experience of any writer's dreams". He added: "I had the best job in show business for four years, and I'll never forget that."

It has been little secret, however, that tensions have been rising between Mr Sorkin and the network that produces the show, NBC. The two sides had an awkward meeting recently to discuss Mr Sorkin's habit of turning in his scripts perilously late – unnerving the actors and greatly increasing the cost of each episode.

Going up against popular reality programmes such as ABC's dating extravaganza The Bachelor and CBS's talent show American Idol, The West Wing has lost 22 per cent of its audience this season. The plotlines have become more extravagant – a technical fault aboard Air Force One, kidnappings, and so on – in a way that has lost the show some of its critical acclaim without luring more viewers.

The Hollywood rumour mill has worked overtime to figure out the problem. Mr Sorkin is exhausted, some say. His politics have become unwelcome, say others. NBC is nervous about the heat it has taken for the off-screen political campaigning by the show's star, Martin Sheen, say yet others.

There is probably some truth in all the rumours. One associate of Mr Sorkin told Variety: "He's said all he wanted to with this show." The entertainment daily also reported that NBC was threatening to curb Mr Sorkin's script independence to make the show be driven more by character than by politics.

Officially, at least, this is far from the end of the road. Earlier this year, NBC signed up for two more seasons of the show, with an option on a third. It agreed to pay three times the previous licensing fee – now up to around $6.5m (£4m) an episode – although industry insiders believe the figure could have been higher still if the ratings had stayed buoyant.

The show will now be taken over by John Wells, currently the number three at The West Wing. Mr Wells is one of the most accomplished producers in the business – ER is his most successful baby to date – with a record of delivering shows on time and under budget. NBC may decide, however, to downgrade the show from its Wednesday evening slot to 10pm on Sunday nights, the first sign that the show is on its way out.

Mr Wells acknowledged that Mr Sorkin and Mr Schlamme were "irreplaceable" and would be "sorely missed". "Sadly, we always knew this day would come," he said, "and have been assembling a talented group of writers, directors and producers to assist in this transition." Translation: enter the B-team.