Ferguson is familiar with several of the Red Knights group, particularly Goldman Sachs top economist Jim O'Neill.
He said: 'I've no issue with the Red Knights. I know some of them, I'm quite friendly with a couple of them. If they want to try to buy the club, it's entirely up to them.
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'But David Gill summed it up when he said the club's not for sale. So what can anyone do?'
When asked what he thought of Harris, the head of investment bank Seymour Pierce, calling on fans to boycott games, Ferguson said: 'Now that's a great idea. That's come from an intelligent guy, has it?'
Ferguson insists he does not mind the protests as long as they do not affect his team. He said: 'I saw plenty of green and gold scarves at Wembley on Sunday, and I was delighted to see them. I'd even take City fans if they wanted to come along. We'll take all sinners. As long as they're supporting United, they can wear what they bloody like!'
Some experts believe the Red Knights will have to find up to £1.5billion to get the Americans to sell, but a spokesman said yesterday they would not pay over the odds.
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