  We consider gauge field theories in the presence of ensembles of vector
backgrounds. While Lorentz invariance is explicitely broken in the presence of
any single background, here, the Lorentz invariance of the theory is restored
by averaging over a Lorentz invariant ensemble of backgrounds, i.e. a set of
background vectors that is mapped onto itself under Lorentz transformations.
This framewkork is used to study the effects of a non-trivial but Lorentz
invariant vacuum structure or mass dimension two vector condensates by
identifying the background with a shift of the gauge field. Up to now, the
ensembles used in the literature comprise configurations corresponding to
non-zero field tensors together with such with vanishing field strength. We
find that even when constraining the ensembles to pure gauge configurations,
the usual high-energy degrees of freedom are removed from the spectrum of
asymptotic states in the presence of said backgrounds in euclidean and in
Minkowski space. We establish this result not only for the propagators to all
orders in the background and otherwise at tree level but for the full
propagator.
