  Classical and quantum world views differ in peculiar ways. Understanding
decisive quantum features -- for which no classical explanation exist -- and
their interrelations is of foundational interest. Moreover, recognizing
non-classical features carries practical significance in information processing
tasks as it offers insights as to why quantum protocols work better than their
classical counterparts. We focus here on two celebrated notions of
non-classicality viz., negativity of P phase-space representation and
entanglement in symmetric multiqubit systems. We prove that they imply each
other.
