Apparently ~620 out of 708 Warrior armoured vehicles are operational but that is intended to decline by 100 this year, 157 out of 227 operational Challenger 2 tanks, etc. not terrible but not ideal either. What could actually be fielded without at least a months prep though is likely less than half those numbers :s
It's okay, remember, it's not a numbers game... according to the minister for defense.
Fewer everything equals better apparently