1997, they introduced a second devolution referendum which resulted in the enactment of the Scotland Act 1998 and the creation of the Scottish Parliament. Unionists took different sides on the debates regarding devolution. Supporters argued that it would strengthen the Union, as giving Scotland self-government would remove the contention that independence was the only way to obtain control over internal affairs. Labour politician George Robertson said that devolution "will kill nationalism stone dead" for this reason. John Smith, a Labour leader who supported devolution, believed it was the "settled will" of the Scottish people. Unionist opponents of devolution argued that granting self-government would inevitably lead to the Union breaking, as they believed it would encourage nationalist sentiment and create tensions within the Union. Labour politician Tam Dalyell said devolution would be a "motorway to independence". His West Lothian question asked why MPs for Scottish constituencies should be able to decide devolved matters (such as health and education) in England, but MPs for English constituencies would have no say over those matters in Scotland. The Conservatives, as a Britain-wide party, fielded candidates in Scotland until the creation of a separate Unionist Party in 1912. This was a separate party which accepted the Conservative whip in the UK Parliament until it was merged into the Conservative Party in 1965. The Declaration of Perth policy document of 1968 committed the Conservatives to Scottish devolution in some form, and in 1970 the Conservative government published Scotland's Government, a document recommending the creation of a Scottish Assembly. Support for devolution within the party was rejected and was opposed by the Conservative governments led by Margaret Thatcher and John Major in the 1980s and 1990s. The party largely remained opposed to devolution in the 1997 Scottish devolution referendum campaign. That referendum was passed with a large majority, the Conservatives have since accepted devolution in both Scotland and Wales. The governments led by David Cameron devolved further powers to the Scottish Parliament in 2012 and 2016. Cameron also attempted to answer the "West Lothian question" by changing the procedures of the UK Parliament (English votes for English laws). Notable opponents of unionism are the Scottish National Party (SNP) and the Scottish Green Party. The Scottish Socialist Party (SSP) and Solidarity seek to make Scotland an independent sovereign state and a republic separate from England, Wales and Northern Ireland. Of these parties, only the SNP currently has representation