Expected amenable subalgebras preserving core commutants

We prove that every inclusion $N\subset M$ of von Neumann algebras with separable preduals and a faithful normal conditional expectation contains an expected amenable subalgebra $P\subset N$ such that $P^{\prime }\cap c(M)=N^{\prime }\cap c(M)$, where $c(M)$ denotes the continuous core of M. This resolves the relative bicentralizer conjecture in this setting.