The first elections to the council were held in 1973, initially operating as a shadow authority prior to the district coming into effect the following year. From 1973 until its abolition in 2019 political control of the council was held by the following parties:[1]
By-elections occur when seats become vacant between council elections. Below is a summary of by-elections from 1997 to 2019;[12] full by-election results can be found by clicking on the by-election name.