RETIRED football commentator Archie Macpherson has emerged as the No campaign's surprise weapon in its fight to keep Scotland in the UK.

The much-loved broadcaster, known to generations of football fans for his passion and purple prose, turned his talents to politics yesterday with a barnstorming speech at a Better Together rally.

Tonight in Glasgow at the annual dinner of business group CBI Scotland, Prime Minister David Cameron will hail the UK as one of the world's "oldest and most successful single markets" as he campaigns to keep the country together.

His visit comes as 200 business people back independence in an open letter published in today's Herald.

Making his debut in the referendum debate, Mr Macpherson, 77, outshone a former Prime Minister and a former Chancellor when he shared a stage with Gordon Brown and Alistair Darling in Dundee.

"Ladies and gentlemen, my name is Archie Macpherson and I'm a pensioner," he told an audience of 300 No supporters at the city's Caird Hall before delivering a withering attack on First Minister Alex Salmond's independence campaign.

He said: "Why did I accept the invitation to speak here? As my wife would verify, anger. Sitting watching the ­obfuscation and evasion streaming out from the independence campaign, I couldn't stand it any longer."

He was "sticking his head above the parapet," he said, because it was "far too important to sit back".

With Mr Brown and Mr Darling relegated to a subs' bench on the stage, the football pundit described his lifelong admiration for the creation of the NHS by the post-war Labour government.

He said: "I don't need to go back to 1320 for a Declaration, I can go back to 1945 when I was a kid in arms and my father held me up in his arms outside the poor house in Shettleston, where I grew up, celebrating that victory in 1945 which changed and transformed society, something we must never forget. Our forbears created the welfare state, the education system from which myself and others have hugely benefited. I intend to stick on that particular road, difficult though it may be."

By now the audience was c­heering loudly for the No campaign's no-nonsense new signing. Mr Macpherson went on: "Within the United Kingdom that is the right and moral road, because I am as concerned about food banks in Liverpool as I am in Glasgow or Dundee."

Values down south, he added, were not so different he wanted to call English people foreigners. "No thanks to that," he said.

He was greeted with a burst of knowing laughter when he mentioned a recent eye operation and added: "It was a procedure many football supporters thought I should have had long ago."

But he went on: "My wife and myself have benefited ­enormously from the NHS and it turns my stomach to see the SNP trying to make political ­capital out of this extraordinary piece of work."