The official opposition following the 2013 election, the purple party lost its grip in key parts of Arun and Adur.
Leader Sandra James lost her Bourne seat to the Conservatives, while the party suffered defeats in Lancing – where it took control of the parish council in 2016.
UKIP lost seats in Bersted, Felpham, Nyetimber, Middleton, Bourne, Selsey, Durrington and Salvington, Lancing and Sompting and North Lancing.
It polled last in the new Shoreham South ward, a ward created following the dissolution of Saltings ward, which the party won in 2013.
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