The Schwinger-Dyson equation for the gluon propagator in the axial gau
ge is considered with account of the gauge identities for the gluon Gr
een's functions. A possibility of soft singular power type infrared be
haviour for the gluon propagator is studied, D(q) similar to (q(2))(-c
), q(2) --> 0 where c is a small positive number. Under certain assump
tions a characteristic equation for the exponent is obtained. This equ
ation is shown not to have solutions in the interval 0 < c < 1.