Well got up after a couple of hours sleep from nights and went out to the bike.
Same symptoms, no cranking. Using the manual and a multimeter I fumbled my way through the tests. All appeared to be in order., so I dismantled the r/h switch to check the killswitch. It is a new switch so all connections looked ok. I cleaned them up a bit and checked the continuity between the points. All ok.
Anyway a bit puzzled, I reassembled all the parts and tried it. It fired up. Switched it off, sat on the bike, tried it again....Nowt. I'm starting to think sidestand switch so, still sitting on the bike, I leaned it over to put some weight on the stand and off it went. Tried it again and nowt. Still holding in the starter switch I sat the bike upright and off it went. Hmm thinks I. I tried the starter with the bars facing straight ahead...nowt I moved the bars slightly to the right and off it went. I repeated this a number of times and each time the bike fired up, so my diagnosis is a loose wire at the starter button. I had checked the killswitch, but never looked at the lower part of the switchgear. Anyway getting ready for nights, so I will look at that tomorrow.
On showing this to my boy, he asks if this could be related to the bike being blown over on Thursday night. Twas very windy and a gust of wind blew the bike over on the righthand side. Hopefully that has dislodged summit obviuos and I'll see it tomorrow.