[en] CsCuCl₃ is a quantum triangular antiferromagnet, ferromagnetically stacked, with an incommensurate (IC) structure due to a Dzyaloshinskii-Moriya interaction. Because of the classical degeneracy caused by the frustration, fluctuations in CsCuCl₃ have extraordinarily large effects, such as the phase transition in longitudinal magnetic field (normal to the planes, parallel to the IC wavenumber q) and the plateau in q in transverse field (perpendicular to q). We argue that fluctuations are responsible also for the new IC phase discovered in transverse field near the Neel temperature T_N, by Werner et al (Werner T, Weber H B, Wosnitza J, Kelnberger A, Meschke M, Schotte U, Stuesser N, Ding Y and Winkelmann M 1997 Solid State Commun. 102 609). We develop and analyse the corresponding minimal Landau theory; the ground-state reconstruction due to fluctuations is described phenomenologically, by means of a biquadratic term. The Landau theory gives two IC phases, one familiar from previous studies; the properties of the new IC phase, which occupies a pocket of the temperature-field phase diagram near T_N, agree qualitatively with those of the new phase found experimentally. (author)