emphasising left-of-centre policies and values was therefore electorally logical for the SNP, as well as tying in with the ideological preferences of many new party members. In 1961, the SNP conference expressed the party's opposition to the siting of the US Polaris submarine base at the Holy Loch. This policy was followed in 1963 by a motion opposed to nuclear weapons: a policy that has remained in place ever since. The 1964 policy document, SNP & You, contained a clear centre-left policy platform, including commitments to full employment, government intervention in fuel, power and transport, a state bank to guide economic development, encouragement of cooperatives and credit unions, extensive building of council houses (social housing) by central and local government, pensions adjusted to cost of living, a minimum wage and an improved national health service. The 1960s also saw the beginnings of the SNP's efforts to establish an industrial organisation and mobilise amongst trade unionists in Scotland, with the establishment of the SNP Trade Union Group, and identifying the SNP with industrial campaigns, such as the Upper-Clyde Shipbuilders Work-in and the attempt of the workers at the Scottish Daily Express to run as a co-operative. For the party manifestos for the two 1974 general elections, the SNP finally self-identified as a social democratic party, and proposed a range of social democratic policies. There was also an unsuccessful proposal at the 1975 party conference to rename the party as the Scottish National Party (Social Democrats). In the UK-wide referendum on Britain's membership of the European Economic Community (EEC) in the same year as the aforementioned attempted name change, the SNP campaigned for Britain to leave the EEC. There were further ideological and internal struggles after 1979, with the 79 Group attempting to move the SNP further to the left, away from being what could be described a "social-democratic" party, to an expressly "socialist" party. Members of the 79 Group – including future party leader and First Minister Alex Salmond – were expelled from the party. This produced a response in the shape of the Campaign for Nationalism in Scotland from those who wanted the SNP to remain a "broad church", apart from arguments of left vs. right. The 1980s saw the SNP further define itself as a party of the political left, such as campaigning against the introduction of the poll tax in Scotland in 1989; one year before the tax