The UK is not the primary owner of BP, JP Morgan is. This is an international company with most shareholders in the US it sounds like or JP Morgan being the largest holder. The US subsidiary can go bankrupt if the company is split and the company may remain solvent as one possible track for the company.
Bear in mind that this rig was owned by Transocean and maintained by Halliburton, BP were just renting it. No doubt BP will be seeking substantial damages in the courts from these two companies once the smoke clears.
BP has become a Pinata, one which a very immature President is taking swipes at in order to bolster his image after making a less than impressive input at the beginning of this tragedy.
The Company will survive and hopefully come out its corner to set matters straight as to who is really resposnible for this this sad event. I am sure that we will find that the blame is rightfully going to be spread around and that the Government itself will not come out of this smelling of roses.
Meanwhile BP makes an easy target, especially with that right wally Hayward at the helm.