Abstract: The assembly comprises a first insulating housing (2) having terminal receiving through cavities (8) each having therein a resilient locking lance (16), and a second insulating housing (4) having through cavities (24). There projects from the front face (26) of the second housing (4) a row of locking lance actuating tongues (38). In a terminal loading position of the housings (2 and 4) the front face (26) of the second housing (4) is spaced from the front face (12) of the first housing (2) so that each tongue (38) projects to some extent beneath a respective locking lance (16). In this loading position, an electrical terminal (68) connected to a lead (L) is inserted through each cavity (24) of the second housing (4) into a cavity (8) of the first housing (2). The housings (2 and 4) are then moved relatively towards one another into a terminal locking position, so that each tongue (38) is advanced further beneath the corresponding lance (16) to lock the terminal in the cavity.