Complex sentence: Rachael Maskell is a Labour frontbench as part of the Shadow Defence Team, working under Shadow Secretary of State for Defence Maria Eagle who was shifted away because of her support for the UK nuclear deterrent.
Split into simpler sentences: Rachael Maskell is a Labour frontbench as part of the Shadow Defence Team, initially working under Shadow Secretary of State for Defence Maria Eagle. Eagle was subequently shifted away because of her support for the UK nuclear deterrent.