Аннотация:We consider the simplest optimal control problem with one nonregular mixed con-straint G(x; u) 6 0; i.e. such a constraint that the gradient Gu(x; u) can vanish on the surfaceG = 0: Using the Dubovitskii{Milyutin theorem on the approximate separation of convex cones,we prove a rst order necessary condition for a weak minimum in the form of the so-called \localminimum principle", which is formulated in terms of functions of bounded variation, integrable func-tions, and Lebesgue-Stieltjes measures, and does not use functionals from (L∞)∗ . Two illustrativeexamples are provided. The work is based on the book by Milyutin [3].