Electric monopoles and the Montonen-Olive conjecture

We introduce a topological field theory with a Bogomol'nyi structure permitting BPS electric, magnetic and dyonic monopoles. From the general arguments given by Montonen and Olive the particle spectrum and mass compare favourably with that of the intermediate vector bosons. In most, if not in all, of its essential features the topological field theory introduced here provides an example of a dual field theory, the existence of which was conjectured by Montonen and Olive.