Husband home, so plugged in my OBDII - which I had a good go at him for, for not putting back in the car after 'borrowing' it. Turns out it's an intermitten MAF fault. Friendly RAC man is coming round tonight or tomorrow to give MAF a clean and if that doesn't work will get part and fit it. Result ! Turns out I could've driven home, but that would have deprived the 4yr old of the drive in the slide bed, which he is still talking about now. Will be changing breakdown service though as 100 minutes waiting time is ridiculous.