Scaling limit of the six vertex model in the framework of free field representation

The scaling limit of the spectrum, S matrix, and of the form factors of the polarization operator in the six-vertex model has been found. The result for the form factors is consistent with the form factors of the sine-Gordon model found recently by Lukyanov. We discuss the origin of the structure of the free field representation for the sine-Gordon model at the critical coupling from the point of view of the lattice model.