  A group theoretical mechanism for unification of local gauge and spacetime
symmetries is introduced. No-go theorems prohibiting such unification are
circumvented by slightly relaxing the usual requirement on the gauge group:
only the so called Levi factor of the gauge group needs to be compact
semisimple, not the entire gauge group. This allows a non-conventional
supersymmetry-like extension of the gauge group, glueing together the gauge and
spacetime symmetries, but not needing any new exotic gauge particles. It is
shown that this new relaxed requirement on the gauge group is nothing but the
minimal condition for energy positivity. The mechanism is demonstrated to be
mathematically possible and physically plausible on a U(1) based gauge theory
setting. The unified group, being an extension of the group of spacetime
symmetries, is shown to be different than that of the conventional
supersymmetry group, thus overcoming the McGlinn and Coleman-Mandula no-go
theorems in a non-supersymmetric way.
