An essential task for the morphosyntactic level within the grammatical component of Functional Discourse Grammar (FDG) is the handling of constituent ordering. This area of grammar, which is known as positional syntax, constitutes the subject of the present paper, in which the ordering of constituents is examined within the framework of a dynamic implementation of the FDG model. First of all, an analysis is presented of how FDG differs from its predecessor, Functional Grammar, in the treatment of constituent order. Next, attention is focused upon the question of how a dynamic FDG-based account of positional syntax may be developed. A linearisation mechanism is proposed which reflects the basic principles of FDG theory, and the working of the mechanism is illustrated in relation to the positional syntax of the English Clause. Some problems are then discussed, and avenues are explored towards their solution.