Charles Tyrwhitt Men's Slim Fit Super 120s Wool Tuxedo Trousers - 38/34 - Black - Available at M&S

Charles Tyrwhitt Men's Regular Fit Pure Wool Suit Trousers - 3834 - Black - Available at M&S

These pure merino wool suit trousers from Charles Tyrwhitt make a refined choice for formal occasions. They're cut in a regular fit with, side adjusters on the waistband so you can tailor them to you. A flat front creates a streamlined silhouette, while a hook bar and zip fastening ensures a neat look.