Labour has bolsted its position as the only Party that can oust the Tories in Peacehaven, Telscombe and East Saltdean.
Labour exceeded expectations at the ballot box at the beginning of May.
The results are part of a wider pattern of Labour successes across Sussex gaining seats and increasing majorities where they lead councils such as Hastings and Crawley.
Here in Lewes District, Labour came a strong second in the poll to elect a Police and Crime Commissioner for Sussex, as well as taking the most number of second-preference votes.
A spokesperson for Meridian Branch Labour said,
“The feedback on the street to our activists here is that there is a clear shift towards Labour within Lewes District with trust in Labour locally high.”