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Though tempting on recent experience, it would be reckless to assume that nothing of any lasting significance will happen at this autumn's three main party conferences, which begin with the Liberal Democrats this weekend. But it may be a pardonable exaggeration to say that the most influential event of the season could be done and dusted before Nick Clegg and his party even get down to business on Saturday. The annual conference of Britain's fourth party is unlikely to get more than passing attention when it gathers in Birmingham tomorrow for two days. But the UK Independence party, now to be officially renamed simply Ukip, is no longer merely a marginal player in the British party battle. If the cards fall Ukip's way over the next two years – and they well may – the party...