- guardian.co.uk, Sunday September 2 2001 11.05 BST
Clarke said it was clear he personally would not appeal to extremists, prompting a furious salvo from Duncan Smith who accused his rival in turn of having failed to do enough to root out racists in the party during the height of his career.
Tempers snapped at a hustings in Scotland as both candidates were responding to claims from Andrew Lansley, the Shadow Cabinet Minister and a leading Clarke supporter, that the party had failed to elect ethnic minority MPs because it was steeped in 'latent racism.'
Lansley's remarks, which will anger many grassroots supporters, posed a tough dilemma for Clarke, who was forced to distance himself from them.
'I raised my eyebrows at the use of the phrase "endemic racism",' he said in Perth, where both candidates were yesterday holding hustings. 'I don't recognise that in the party. But every other word in the article I agree with.'
He added that Duncan Smith was not remotely racist himself 'but the party is moving so far to the right we are beginning to attract the lunatic fringe.
'Whatever quality I might claim for myself, I do not appear to attract the lunatic fringe.' The comment was seen as an implication that Duncan Smith would.
Sensitive after days of allegations that some of its supporters have links to the far right, Duncan Smith was swift to return fire.
'Why Ken has only just discovered this [extremism] now is beyond me,' he said. 'These people have been in the party under Ken, and under Major. Why didn't Ken do something about them then?'
Aides said it was 'totally ridiculous' to suggest Duncan Smith was appealing to the lunatic fringe.
Earlier the increasingly bad-tempered battle took a fresh twist with allegations of 'dirty tricks' against the Duncan Smith team. Clarke aides said rightwingers had been deliberately planted to disrupt their hustings over the last few weeks with volleys of hostile questions about Europe.
'Ken told me that at one of the meetings it was perfectly obvious that a few people from the IDS campaign had been planted and that they made a lot of noise.There is quite a bit of barracking and it's no coincidence that so many of the questions are about Europe,' said one senior MP.
Aides said stooges had been seen clutching pieces of paper with five damaging questions to ask Clarke. 'It is definitely organised, and this is not a random selection of people. There are some silly games going on,' said one.
Clarke had also suggested that his rival was not up to coping physically with the strains of a hectic campaign.
In an interview with the Daily Mail, he said he could manage perfectly happily on four hours' sleep - as Margaret Thatcher famously claimed she could - but that 'every time I see Iain he tells me how tired he is.'
Responding to Lansley's comments, Duncan Smith said he believed the party was 'tolerant and inclusive' already but that he would try to reach out to people 'regardless of creed, colour and religion'.
However, he was promptly attacked by the Tory peer Lord Taylor of Warwick, a longtime campaigner on race issues. He argued that Duncan Smith's credibility with ethnic minorities was low because as a former member of the Hague shadow cabinet his 'fingerprints are all over William Hague's disastrous leadership'.
