  An effective low energy action for Yang-Mills theories is proposed, which
invokes an additional auxiliary field $H_{\mu \nu}$ for the field strength
$F_{\mu \nu}$. For a particular relation between the parameters of this action
a gluon propagator with a $1/p^4$ behaviour for $p^2 \to 0$ in the Landau gauge
is obtained. The abelian subsector of this action admits a duality
transformation, where the dual action contains a Goldstone boson $\varphi$ as
the dual of $H_{\mu \nu}$, and corresponds to an abelian Higgs model in the
broken phase describing the condensation of magnetic charges. The Wilsonian
renormalization group equations for the parameters of the original action are
integrated in some approximation, and we find that the relation among the
parameters associated with confinement appears as an infrared attractive fixed
point.
