In March 1981 the SDP was founded. In May 1981 Donald Hoodless became the new Labour Leader and council leader. In September 1981, following the resignation of a Labour councillor, the SDP gained a council seat in Hillarton ward. In December 1981 over half of the Labour group on the council resigned the Labour whip and joined the SDP. This gave the SDP a majority of seats and their leader, Jim Evans, became the new council leader. Divisions within the SDP saw the emergence of a separate Social Democrat group that included four sitting SDP councillors. This group stood in the 1982 elections in opposition to official SDP candidates.