Yes, you are right to be worried about it. Accidents don't take a holiday at Christmas, in fact it’s their chance for a bit of overtime.
Cutting staff numbers (or significantly changing shift patterns) is a change to the way of working and therefore your employer should carry out a fresh risk assessment which takes into account the changes. The risk assessment should, amongst other things, look at:
- what is the safe number of people who should cover the shift (and why);
- what kind and level of supervision is required (and why); and
- whether the emergency procedures have been amended, and the staff trained or informed of the changes.
You have a right to ask for a copy of the risk assessment. If you have any concerns after this, or your employer has not (or will not) do a risk assessment, raise this with your employer or contact your union rep. If you are not in a union, contact the Health and Safety Executive (HSE) in confidence.