M&S Uniform Size Guidance

I got a job at M&S and I need to tell them the sizes I need for the uniform they’ll order for me.

There wasn’t a size guide provided so I’m not sure what I should order.

I’m about 6/8 for both top and bottoms, but I’m not sure what the actual uniform is like.

Does anyone working at M&S have any guidance they can provide information about this?