In a large bowl, mix mayonnaise, egg, Dijon mustard, Worcestershire sauce, Old Bay seasoning, lemon juice, and parsley.
Gently fold in the lump crab meat and crushed saltine crackers, ensuring the mixture holds together.
Shape the mixture into 6 crab cakes and refrigerate for 30 minutes to firm up.
Heat butter in a large skillet over medium heat and cook the crab cakes for about 3-4 minutes per side, until golden brown.
Serve hot with lemon wedges and tartar sauce.