Modern Vespa

Went for a run out on my GTS250 when i got home left the scoot ticking over while i was opening the garage door but literally within seconds of getting off the scoot it it spluttered & stalled and now it wont start,when i turn the key everything lights up as it should do and the fuel pump energizes but the engine won't turn over,not even a click on the starter motor.
I have disconnected the kill switch which was my first though but still nothing and have now got the battery on charge but i'm unable to tell how much voltage i have in the battery until i get a tester but the battery is less than two years old so i'm not convinced that's the problem.

I read on here that the battery needs a minimum 10v to start the engine but if that's the case would the lights,horn,oil light etc still work as if there wasn't a battery issue.
Thanks in advance...

Well it started and spluttered into life after 3 hours of having the battery on trickle charge.

Unfortunately, since it died while running, I suspect your battery is on it's way out (don't trust it).
Time to get a cheap multimeter and check out your charging system.
If you do a lot of 5 to 10 minute rides the battery isn't charging back up before you stop. If that's the case leaving the battery on the trickle charger once a week will help.

Yeah,was thinking the same thing so have just ordered a Motobatt battery and i'm going to get a decent "all sing all dancing" charger this weekend.

Fitted a new battery and it stalled again and is spluttering at low revs so i'm no better off even with a new battery fitted.

Check the charging system. It sounds to me like the battery is not being charged by the stator.

It's a bad wire,just given the wiring harness a pull and it cuts out everytime i pull on a certain area of the harness.

Just had the same problem. Had the wires and plastic connectors replaced in the wiring harness that went from strator to voltage regulator. Shorted wire seemed to be at the back end of the wiring harness. Replaced with heavier duty wire and connector.

Don't feel bad about the battery-I threw out one that was probably good for another year and returned the first new one for a replacement. All Motobatts.

Cheaper than replacing the stator or regulator/rectifier. You can narrow down the specific wire with a voltage drop test and/or a continuity and resistance test.

Does this happen only when the scooter is on the stand? Does this ever happen when you are sitting on the scooter while it is running?

No need for guesswork. A multitester/voltmeter can be had for less than £5 although I would recommend spending a little more ( try Maplins). Engine stalling may have nothing to do with battery charging but you must eliminate it by measuring battery voltage before and after switching on and with engine idling and at medium rpm. Post this information and plenty of people will be able to help you.