  Investigation of the structure of the Standard Model effective potential at
very large field strengths opens a window towards new phenomena and can reveal
properties of the UV completion of the SM. The map of the lifetimes of the
vacua of the SM enhanced by nonrenormalizable scalar couplings has been
compiled to show how new interactions modify stability of the electroweak
vacuum. Whereas it is possible to stabilize the SM by adding Planck scale
suppressed interactions and taking into account running of the new couplings,
the generic effect is shortening the lifetime and hence further destabilisation
of the SM electroweak vacuum. Absolute stability can be achieved by lowering
the suppression scale of higher order operators while picking up such
combinations of new couplings, which do not generate new deep minima in the
potential. We discuss the issue of gauge dependence of the perturbative
determination of the tunnelling rate and show how this rate can be made gauge
independent at the leading nontrivial order of the RGE improved effective
action.
