To investigate the possibility of a ghost-antighost condensate the coupledDyson--Schwinger equations for the gluon and ghost propagators in Yang--Millstheories are derived in general covariant gauges, including ghost-antighostsymmetric gauges. The infrared behaviour of these two-point functions isstudied in a bare-vertex truncation scheme which has proven to be successful inLandau gauge. In all linear covariant gauges the same infrared behaviour as inLandau gauge is found: The gluon propagator is infrared suppressed whereas theghost propagator is infrared enhanced. This infrared singular behaviourprovides indication against a ghost-antighost condensate. In theghost-antighost symmetric gauges we find that the infrared behaviour of thegluon and ghost propagators cannot be determined when replacing all dressedvertices by bare ones. The question of a BRST invariant dimension twocondensate remains to be further studied.
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