One of the best Apocolyptic TV series made, though I think it tended to tail off. There were 3 series made from 1975. According to the September 2006 SFX magazine the BBC are in talks to resurrect it.
It's understood that the BBC wants to make a new series of six hour-long episodes. The project is being overseen by Beeb producer Sarah Hogg. But a deal has yet to be finalised and the BBC is still in negotiations with Terry Nation's estate.
Although Nation owns the rights to the series, he left after season one, going on to create Blake's 7.