Hi Guy.
On various field trips I have seen several specimens in Greece at least 2 metres in length. In Morocco I came across an adult of about 1.5m which had just seized an adult Agama bibroni. I was able to observe the snake with its prey and, interestingly, no chewing action was observed, the agama just held firmly in its mouth. After a minute or so I attempted to catch the snake which released its prey and made off, dissapearing quickly into a hole in the ground. The agama, despite not being chewed as is usually stated in literature was completely lifeless. Certainly large adults are to be treated with respect as their venom could well be stronger than is generally reported. 

Hi David,
Many thanks for your answer.
Very fast they are, these snakes. I caught mine by dismantling a low wall it had taken refuge in, and using a stick to immobilise it when it shot out. Released it, perfectly healthy, after a couple of days of observation. That was in the Var region of southern France. Very muscular and intimidating animal. At 2.5m they must be quite awesome!
Didn't know about the chewing bit - can you supply a link to a page dealing with this.
Happy herping.
Guy