Iraq drama The Mark of Cain has been rescheduled by Channel 4 following the dispute with Iran over the 15 sailors taken captive in the Shatt al Arab waterway

The two-hour drama was due to air tomorrow at 9pm, but Channel 4 said this morning it would postpone the programme.

Channel 4 initially set May 17 as the rescheduled air date, but following this afternoon's announcement that the group are to be released, the broadcaster said it may look for an earlier date.

Written by Tony Marchant, Mark of Cain deals with the experiences of two northern childhood friends, Wayne and Mark, who are sent to Basra in 2003 after enlisting in the army at 18.

Liza Marshall, the Channel 4 commissioning editor for drama, said this morning: "Channel 4 believes The Mark of Cain is a powerful and significant drama which raises important questions about the brutalising effect of war and the difficulty of exercising moral courage within the army culture. We believe it is entirely legitimate for Channel 4 to explore difficult issues through drama and it is our intention to broadcast this film at the earliest appropriate moment," she added.

The channel will now show a repeat of Challenger - Countdown to Disaster in the slot instead.