WordNet (r) 3.0 (2006):

ultraconservative
    adj 1: extremely conservative
    n 1: an extreme conservative; an opponent of progress or
         liberalism [syn: reactionary, ultraconservative,
         extreme right-winger]

Moby Thesaurus II by Grady Ward, 1.0:

57 Moby Thesaurus words for "ultraconservative":
   Bircher, Bourbon, Tory, anarchistic, anarcho-syndicalist, backward,
   conservationist, conservatist, conservative, die-hard, diehard,
   extreme, extreme right-winger, extremist, extremistic, fogy,
   fogyish, hard hat, imperialist, laudator temporis acti,
   mildly radical, monarchist, mossback, nihilistic, nonprogressive,
   old fogy, old school, old-fashioned, old-fogyish, old-line,
   opposed to change, pink, preservative, radical, radical right,
   reactionarist, reactionary, reactionist, red, revolutionary,
   revolutionist, right, right of center, right wing, right-wing,
   right-winger, rightist, royalist, social Darwinist, standpat,
   standpatter, stick-in-the-mud, subversive, syndicalist, ultraist,
   ultraistic, unprogressive