IANAL, but a quick search yielded this, which is consistent with my experience. Not saying I've used a lawyer in a severance battle, but stories from our HR department indicate that they will offer a month per year exactly for the reason to avoid these legal battles. I couldn't believe the cheque we wrote a fourth year EIT that I had to let go a couple years ago.
http://www.wrongfullydismissed.com/N..._Strategy.html
I am curious though how the sale of the company would impact this. Quite possibly not in favour of the employee.