Sounds like a nightmare. Is there any way I can alter terms and conditions or reduce staff numbers?
You can only do it if you have what is called an ETO reason (ie an economic, technical or organisational reason) for making the changes to the terms or dismissing staff. (Yes, even if the employee consents to the changes.) The ETO reason must entail changes in the workforce – ie, you do not need so many, or you need to change their job functions (the example given in the Government guidance is moving from a managerial to a non-managerial role, or from a sectretarial to a sales role). If you can find an ETO reason, then you are permitted to change terms and conditions, or make redundancies.