  We report direct experimental evidence that the insulating phase of a
disordered, yet strongly interacting two-dimensional electron system (2DES)
becomes unstable at low temperatures. As the temperature decreases, a
transition from insulating to metal-like transport behaviour is observed, which
persists even when the resistivity of the system greatly exceeds the quantum of
resistivity h/e^2. The results have been achieved by measuring transport on a
mesoscopic length-scale while systematically varying the strength of disorder.
