  We analyze nonequilibrium lattice models with up-down symmetry and two
absorbing states by mean-field approximations and numerical simulations in two
and three dimensions. The phase diagram displays three phases: paramagnetic,
ferromagnetic and absorbing. The transition line between the first two phases
belongs to the Ising universality class and between the last two, to the direct
percolation universality class. The two lines meet at the point describing the
voter model and the size $\ell$ of the ferromagnetic phase vanishes with the
distance $\varepsilon$ to the voter point as $\ell\sim\varepsilon$, with
possible logarithm corrections in two dimensions.
