My first post as I was stuck, and now I think I have the answer here - thanks!
Mrs. 255 got stranded on Saturday, because my Laguna II would not start. I got her to check the gearstick was neutral, as this had been a previous problem, but this was not it, so I went to the rescue.
Turned out I now have to depress the clutch to enable the start function. This is not intermittent. Then realised that the reverse lights/parking sensor were inoperative as well, so I figure these are linked.
So, I believe there is a switch on the gearbox which has failed, and is causing both faults. Am I (probably) right?
Anyone got any ideas how much a replacement one is, and if they are a ***** to fit?