Black cotton school trousers!

[KnitterInTheNW]

My poor 15 year old is bursting out of his school trousers hulk style, and I can't find a single pair of school uniform friendly, black, cotton trousers anywhere to fit him. Up to now he's had M&S ones, but they don't seem to have them any more. We need age 16. Has anyone seen any that they could point me in the right direction to, please?
The closest I've found are chinos from next, but he tried them on and they look kind of casual.

Black cotton chinos from next men's. these

Sorry, just read your whole post and seen that these don't work for you x

How long does he need to wear them for? Is he leaving school soon? How strict are the school? Would the chinos make do at least for the summer term?

Matalan?

He's coming to the end of year 10, so still another year after this school year has ended.

I've just ordered some of the skinny fit next chinos to try, to see if they look less relaxed.

I'll go and look at Matalan now, thanks for that suggestion.

I would be looking in the men's section at his age. There would be more choice.