  In a pioneering paper on the role of gravity on false vacuum decay, Coleman
and De Luccia showed that a strong gravitational field can stabilize the false
vacuum, suppressing the formation of true vacuum bubbles. This result is
obtained for the case when the energy density difference between the two vacua
is small, the so called thin wall regime, but is considered of more general
validity. Here we show that when this condition does not hold, however, {\it a
strong gravitational field (Planckian physics) does not necessarily induce a
total suppression of true vacuum bubble nucleation}. Contrary to common
expectations then, gravitational physics at the Planck scale {\it does not
stabilize the false vacuum}. These results are of crucial importance for the
stability analysis of the electroweak vacuum and for searches of new physics
beyond the Standard Model.
