Thank you for your reply John.
When making a redundancy, the first step is to decide is whether an individual is self-selecting for redundancy or whether it is appropriate to identify a "pool" to select employees from.
From your information, it looks like a pool has been identified mi.e. all Deputy Managers have been placed on notice of redundancy.
"The company have been asked by their client to reduce overall **** management costs, so they have decided to place all Deputy managers who work at the 3 different premises on redundancy notice."
Once the pool has been identified and a clear statement has been made identifying the pool of employees from which the redundancies are to be selected, the employer should define a selection criteria which is objective and clearly defined in order that it be consistently and fairly applied to all of the employees who are under notice of redundancy.
Selection criterion commonly used is length of service, attendance record, disciplinary record, skills and experience etc..
From your information, it looks like the company have included your partner in the pot because she is part of the selection pool. This is because she is employed to undertake the same job as the other 2 deputy managers. If she was not included, the redundancy of the other deputy managers could be deemed as unfair because the reason for the redundancy is to 'reduce management costs'.
As your wife is included in the pot, a redundancy which is handled fairly would have all deputy manager's under notice of redundancy, with with one post at x location to be retained. The selection criteria is applied and the two deputy managers who score the least are made redundant.
Feel free to come back with further info after the meeting today