Complex sentence: Dr William Mark Hughes (18 December 1932-19 March 1993) was Labour Member of Parliament for Durham from 1970 to 1983, and the (slightly renamed) City of Durham from 1983 to 1987, when he stood down.
Split into simpler sentences: Dr William Mark Hughes (18 December 1932-19 March 1993) was a Labour politician. Hughes was Member of Parliament for Durham from 1970 to 1983, and the (slightly renamed) City of Durham from 1983 to 1987, when he stood down.