  In this paper we improve the existing order parameter for monopole
condensation in gauge theory vacuum, making it gauge-invariant from scratch and
free of the spurious infrared problems which plagued the old one. Computing the
new parameter on the lattice will unambiguously detect weather dual
superconductivity is the mechanism for color confinement.
  As a byproduct we relate confinement to the existence of a finite correlation
length in the gauge-invariant correlator of chromo-electric field strengths.
