(For spending over £35), be aware the men's sizing in the size guide online is wrong.
It shows large as 9-10 or 43-44.5 so that's what I ordered for size 9 DH but the large has arrived are actually 10-11 or 44.5-46 and are way too big.
Trip back to M&s for me. Have told M&S so, you never know, their website may get updated but I'm not holding my breath.