Scottish MPs have changed the outcome of four elections since 1945, according to figures from the House of Commons library. Governments that would not have been elected without votes from Scotland have, among other things, abolished the death penalty and held referendums on Britain's membership of the forerunner to the EU, the European Economic Community. Without Scottish votes, we would currently have a Conservative majority government.
The Conservatives would have been the largest party in February 1974 but would not have had a majority without Scottish MPs being part of the UK. Labour was the largest party but they did not have a majority, leading to a second general election in October.
Scotland allowed Labour to win a House of Commons majority in October 1974. Harold Wilson once again become prime minister, under a manifesto which pledged to renegotiate the terms of Britain's membership of the European Economic Community (EEC), now the European Union. In power he held a referendum on whether the United Kingdom should stay in the EEC.
The Conservatives would have won an outright majority instead of no overall control in the 2010 election had it not been for Scotland. Nick Clegg has previously said he has blocked 16 Tory policies, including reviving O-levels, raising the inheritance tax threshold and ditching the Human Rights Act.