ALEX Salmond has accused the pro-union lobby of using smoke and mirrors and a campaign mired in negativity to try to defeat his bid to make Scotland independent.

The First Minister lashed out after former chancellor Alistair Darling formally launched the Better Together campaign, which aims to keep Scotland part of the United Kingdom, by declaring independence was an "inadequate response" in a "big and difficult world" going through uncertain and turbulent economic times.

Mr Salmond claimed Mr Darling had made a "threadbare case" in which he had said "not a single word about the anti- independence campaign's alternative vision of more powers for the Scottish Parliament".

He added: "That is because, at heart, this is a Tory-led campaign, which is intent on conceding nothing to the people of Scotland, and hiding behind its refusal to spell out an alternative policy before the referendum."

Mr Darling insisted Better Together would rely on making a positive case which celebrates "not just what makes us distinctive but also celebrates what we share".

He said: "We are positive about our links with the rest of the United Kingdom, through families and friendships, through trade and through shared political, economical and cultural institutions."

He also raised the spectre of a border between Scotland and England and the prospect of turning "our biggest market into our biggest competitor".

Mr Darling added: "This is no abstract debate. It's about jobs, and pensions, and the welfare state, and the survival of businesses."

However, Mr Salmond said: "No rational person seriously believes that England would cease to be a major market for Scotland's goods – and Scotland for England's – following independence."