Amid all the discussion in Tory circles about whether the next election will have more in common with the narrow victory of 1992 or the landslide defeat of 1997, nobody has ever made the case for 1993. But after the Conservatives’ shattering loss of two of their nominally ‘safest’ seats to Labour in by-elections in Tamworth and Mid-Bedfordshire last night, it is time for that year to be given a podium in the debate.