Let $\mathfrak g$ be a Lie algebra which is not reductive. Let $T(\mathfrak g)$ and $U(\mathfrak g)$ be the tensor algebra and universal enveloping algebra of $\mathfrak g$ respectively. We have a cannonical surjection $p: T(\mathfrak g) \rightarrow U(\mathfrak g)$. Does it give a surjective map from $T(\mathfrak g)^{\mathfrak g}$ to $U(\mathfrak g)^{\mathfrak g}$ ? Here $T(\mathfrak g)^{\mathfrak g}$ (resp. $U(\mathfrak g)^{\mathfrak g}$) are the $\mathfrak g$-invariants of $T(\mathfrak g)$ (resp. $U(\mathfrak g)$).