Sas,
Not sure how it would affect things, but if the guys are 60 and over BGI will have employed them as contractors, i.e. on a day rate and with a very short notice period etc. They won't have staff rights so unless things have changed since the last time Mobil did this they don't even have to give a reason for dismissal.
But of course I stand to be corrected
Cheers,
NEO