Space-saving spare tyres suitable for towing?

Kestrel

We are about to change our Toyota Corolla for a Qashqai Acenta 2.0l diesel and have been told that the spare wheel is the 'space saving' type only suitable for driving at 50 mph to the nearest garage in the event of  a puncture.  Is it safe to tow a caravan
with this type of spare wheel or should I invest in a 'proper' spare wheel?