and still dominated that scene at the start of the 1980s. By 1977, the NF was England's fourth largest political party in terms of electoral support, a level of success which—according to Thurlow—"testified to the significance" of the immigration issue in 1970s British politics. Along with Tyndall's BNP, the NF was the most significant far-right group in Britain in the second half of the 20th century, according to Durham. The party also helped shape new far-right subcultures, for instance by cultivating the early white power skinhead music scene. Billig suggested that the NF's long-term importance might have been in keeping anti-Semitism alive in Britain at a time when, following the Holocaust, it was weakened. Billig also argued that the NF helped tilt British politics to the right, encouraging the Conservatives to take a harder stance on immigration under Thatcher's leadership. During the NF's 1970s heyday, the mainstream media only occasionally paid it attention; the NF claimed that this was part of a conspiracy against the party. It often had a better relationship with local newspapers, which were more likely to publish letters sent in by the NF. In the 1970s, NF branches often sought good relations with police to ensure protection of NF events. While the party acknowledged sympathy for its views among the lower ranks of the police, it maintained that the police hierarchy was part of the conspiracy against it. During the 1970s, the party had cells among prison officers. By 2011, both the prison service and police had forbidden their employees from being NF members. Opposition Major social and political groups largely ignored the NF's rise, hoping that depriving it of publicity would hasten its decline, although Jewish and leftist groups took a more proactive approach to opposing it. Leftist approaches varied: the Communist Party of Great Britain and Labour Party Young Socialists mobilised the labour movement against racism to diffuse the NF's appeal, while the International Marxist Group and the International Socialists/Socialist Workers Party favoured direct action to disrupt the NF, holding to the slogan: "No platform for fascists". In 1974, the National Union of Students adopted a "no platform" policy regarding the NF, while the Labour Party forbade its candidates from sharing public platforms, radio, or television slots with NF candidates. 120 Labour-controlled councils banned the party from using local municipal halls. Labour and the Trade Union Congress (TUC) helped mobilise the trade union movement