  In this paper, we prove the strong unique continuation property at the origin
for solutions of the following scaling critical parabolic differential
inequality
  \[
  |\operatorname{div} (A(x,t) \nabla u) - u_t| \leq \frac{M}{|x|^{2}} |u|,\ \ \
\
  \]
  where the coefficient matrix $A$ is Lipschitz continuous in $x$ and $t$. Our
main result sharpens a previous one of Vessella concerned with the subcritical
case as well as extends a recent result of one of us with Garofalo and Manna
for the heat operator.
