Plot: David Dimbleby presents the topical debate from Falkirk, with Scotland's deputy first minister Nicola Sturgeon MSP, Liberal Democrat secretary of state for Scotland Alistair Carmichael MP, former leader of the Scottish Conservatives Annabel Goldie MSP, Labour's shadow Scottish secretary Margaret Curran MP, co-convenor of the Scottish Greens Patrick Harvie MSP and the singer-songwriter and member of Artists for Independence Eddi Reader.