It goes to the soul: John Swinney is under threat as he has never been before

The challenger is Dr Bill Wilson, a party convener from Glasgow who switched to the SNP from Labour in the late 1980s. A bright man by all accounts - he used to be employed in Glasgow University's Department of Zoology but is now doing IT work for an insurance company - he hasn't had much success in politics. In the May election he was roundly thumped by Labour, although it was the SSP that did the whipping, stealing nearly 11 per cent of his share. He is a symbol, and a victim, of the SNP's failure in West Central Scotland.

Wilson is also part of a small clique of activists who consider themselves as SNP 'fundamentalists'. They were opposed to the stock transfer of Glasgow council houses, which they believed cost them votes in the election. They are opposed to a referendum on independence. They are opposed to the 'New Labourisation' of the SNP. Their attitude is seen by others to be almost entirely negative. The Observer