Let $V$ be a multiset of $kn$ nonzero vectors in $\mathbf{R}^n$. Suppose that for $1 \leq d \leq n$, each $d$-dimensional subspace of $\mathbf{R}^n$ contains at most $kd$ members of $V$. Then $V$ can be partitioned into $k$ bases of $\mathbf{R}^n$.
A proof or a reference would be appreciated.