When redundancies were made at my last outfit it was made very clear that LIFO is no longer a legitimate way of selecting those for redundancy
Going a little off-topic but it's amazing how quickly managers trot this line out when it suits them and how ignorant they are. The recent age discrimination legislation does allow an employer to consider length of service when determining the reward an employee receives, if you want to look it up it's Section 32 of the Employment Equality (Age) Regulations 2006.
Of course if your employer chooses not to use LOS as a criteria for redundancy then that's up to them but it has nothing to do with it being unlawful, as the recent Rolls-Royce case demonstrated, and much more to do with finding an excuse to select the cheapest employees to make redundant.