The British Labour Party has spent eighteen years in opposition since 1979. During that time it lost four consecutive general elections to the Conservative Party. In 1997, however, it now looks set to win its first election since 1974. This thesis examines the Labour Party in opposition since 1979, using a theoretical framework informed by Anthony Giddens' structuration theory. Based on a dialectical notion of the structure and agency linkage, a two-tiered framework is constructed which at one level views a political party as consisting of a set of structures which can constrain and enable party leaders in their attempts to make the party electorally successful, and at another level the party is regarded as a collective agent in its own right, which in turn is subject to the effects of larger external structures. By comparing the strategies adopted by the Labour Party and its leaders since 1979, the thesis demonstrates that the apparent recovery in the Party's electoral fortunes has corresponded with an increase in the ability of agents to successfully negotiate structural constraints, whilst taking advantage of enabling structures. However, it is also clear that the transformation of Labour into an electorally viable party in 1997 is not solely the product of agency in the period since the last election; rather, it is the culmination of a longer-term process of party change.