OK, thanks. Voluntary redundancy is when you put yourself forward for redundancy and the employer accepts your application and makes you redundant as a result. If only one of you applies and is made redundant as a result the that would be VR. If both apply and the employer chooses one over the other, it would still be VR.
If no one applies for VR and the employer then has to choose who is selected for redundancy, that is when it will be compulsory redundancy.
Unfair dismissal will potentially occur if you are unfairly selected for redundancy or the employer does not follow a fair procedure (no consultation and no offer of suitable alternative employment).
It is entirely possible that the other employee may be selected for redundancy by the employer as it will depend on what selection criteria they choose to apply, but if that happens then you can always reject the offer they have made you as being unsuitable. That would then allow you to ask for redundancy and if the employer refuses it, you will have to consider resigning and claiming constructive dismissal instead.
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