Confidence: It's likely to be this, but I can't be certain.
Notes: Approx. 4-5 cm tall with striking 'spikes'. No particular smell (ruling out stinking puffball) but I thought common puffballs had knobbled warts rather than spikes. Incidently, the species was not dark brown indicating it unlikely (but not impossible) that it was a 'Spiney Puffball'. Any help welcome.