Necessary and sufficient conditions for the functional central limit theorem for semimartingales

Suppose that $X^n$, $n\ge 1$, is a family of semimartingales with the triplets of local characteristics $(B^n,\langle X^{nc}\rangle,\nu^n)$ and $M$ is a continuous Gaussian martingale. We find conditions which are necessary and sufficient for the weak convergence $X^n\overset{\mathscr D}{\to}M$ ($n\to\infty$).