  The existence in the physical QCD vacuum of nonzero gluon condensates, such
as $<g^2F^2>$, requires dominance of gluon fields with finite mean action
density. This naturally allows any real number value for the unit ``topological
charge'' $q$ characterising the fields approximating the gluon configurations
which should dominate the QCD partition function. If $q$ is an irrational
number then the critical values of the $\theta$ parameter for which CP is
spontaneously broken are dense in $\mathbb{R}$, which provides for a mechanism
of resolving the strong CP problem simultaneously with a correct implementation
of $U_{\rm A}(1)$ symmetry. We present an explicit realisation of this
mechanism within a QCD motivated domain model. Some model independent arguments
are given that suggest the relevance of this mechanism also to genuine QCD.
