Consisting of that part of the Regional Municipality of Halton comprised of:

(a) the Town of Milton; and

(b) that part of the City of Burlington lying northwesterly of a line described as follows: commencing at the intersection of the northeasterly limit of said city with Highway No. 407; thence generally southwesterly along said highway to Dundas Street; thence southwesterly along said street to the southwesterly limit of said city.