  Macro-realistic description of systems is based majorly on two basic
intuitions about the classical world, namely, macrorealism per se, that is, the
system is always in a distinct state, and non-invasive measurements, that is,
measurements do not disturb the system. Given the assumption of no-signalling
in time, one utilizes Leggett-Garg inequalities to observe a violation of
macroscopic realism which requires at least three measurements. In this work,
we show that if one has access to shared randomness then one can observe a
violation of macroscopic realism using a single measurement even if no
signalling in time is satisfied. Interestingly, using the proposed scheme one
can also rule out a larger class of models, which we term "macroscopic
no-signalling" theories which can not violate the no-signalling in time
conditions. We further construct a witness to observe the violation of
macroscopic no-signalling.
