I have finally traced the cutting out problem on my 2009 Panda Active Eco.
It mysteriously started cutting out when going over a bumpy road surface, speed bumps and on deceleration and acceleration.
The culprit was that the smaller of the ECU jack plugs was not seated properly.
Whilst letting the car tick over I started to systematically check all the relays and fuses for correct seating and then moved onto the jack plugs on top of the ECU. As I wobbled the smaller of the two jack plugs, the engine cut out.
Did it again, same result.
I removed the offending jack plug, cleaned any dust/debris away and refitted it.
No further problems at all. Runs perfectly.

Hope this info will assist anyone with the same problem.

Lach.

Don't hold your breath it won't happen again.

It's noted that the Active models have a dodgy wire in the loom that causes various injector or coil fault codes and cutting out over bumps.

At least one has managed to fix it themselves.
https://www.fiatforum.com/panda/420817-injector-problem-code-p0202-cyl-2-injector.html