  We show that deformations of a coisotropic submanifold inside a fibrewise
entire Poisson manifold are controlled by the $L_\infty$-algebra introduced by
Oh-Park (for symplectic manifolds) and Cattaneo-Felder. In the symplectic case,
we recover results previously obtained by Oh-Park. Moreover we consider the
extended deformation problem and prove its obstructedness.
