Redundancy is a minefield with different bodies applying the same laws in different ways. And the European laws are different to the UK laws. I expereinced this post 9/11 - here is a little of what I learned.
The Employment Rights Act of 1996 requires that an employer prrove that selection of redundees was done fairly, a simple policy of LIFO is not always enough. One element of this is that an employee is not made redundant - it's his or her job that is redundant. So if an employer, as part of the downsizing decides to dispose of an aircraft type, the pilots on a remaining fleet cannot be made redundant if the more senior pilots from the fleet which has been cut are retrained to take their jobs. In this case, they are 'dismissed for reasons of redundancy' but not technically made redundant themselves. These pilots may have a case for unfair dismissal. But beware, the statutory redundancy payments which tend to be the maximum awarded by an employment tribunal are not very generous. A settlement made directly with the employer is usually more benficial to the employee.
Another thing, if an employer finds another job before his or her redundancy date and resigns, they forfeit any claim for redundancy pay. They should hang on in there or write a carefuly worded letter stating that they have found another job and are having to take an earlier redundancy date. An employer making someone redundant cannot prevent an employee from leaving early to take up a new position. In any case, never use word 'resign'.