Now based in Battersea, Tyndall left Jordan and the NSM and formed his own rival, the Greater Britain Movement (GBM). According to Tyndall, "the Greater Britain Movement will uphold, and preach, pure National Socialism". According to the political scientist Stan Taylor, the GBM reflected Tyndall's desire for "a specifically British variant of National Socialism". It called for the criminalisation of sexual relations and marriages between white Britons and non-whites and called for the sterilisation of those it deemed unfit to reproduce. The group established its base in a run-down building in Notting Hill, with swastikas being sprayed onto the exterior and an image of Hitler decorating the interior. Tyndall tried to convince the WUNS to accept his GBM as its British representative, but Rockwell—concerned not to encourage schismatic dissenters in his own American Nazi Party—sided with Jordan and the NSM. Tyndall then established contact with Rockwell's main rival in the American neo-Nazi scene, the National States' Rights Party.