The aim of this research is to investigate the post1997 Parliamentary Conservative Party, with particular attention placed upon the Conservative Party leadership election of 1997 and 2001. The thesis uses these two leadership elections as a lens which can be utilised to focus upon and analyse the ideological disputations of contemporary British Conservatism. This is done by identifying the voting behaviour of Conservative parliamentarians in the two leadership elections and then by putting forwards a systemic explanation of the candidates’ support. Three sets of variables are tested. First, the thesis analyses socio-economic variables (i.e. the occupational and educational background of conservative parliamentarians). Second, the research considers the candidates’ support in relation to electoral and political variables (i.e. electoral vulnerability, political insider / outsider status, age and experience). Finally the research will evaluate the candidates’ support with regard to the ideological disposition of the candidates and their supporters. This requires an extensive exploration of the attitudes of Conservative parliamentarians with regard to the dominant ideological divides within contemporary post- Thatcherite Conservatism – economic policy (wet / dry), European policy (europhile / eurosceptic), and social, sexual and moral attitudes (social liberalism / social conservatism). By analysing the patterns of voting in relation to social background, political attributes and ideological disposition the thesis locates and interprets the differing motivational influences on voting behaviour. The thesis argues the ideological disposition of the candidates and their supporters was the crucial factor in both the leadership elections. The final round of the 1997 leadership election was a straight ideological battle between the europhile and eurosceptic wings of the parliamentary Conservative Party. This benefited the eurosceptic William Hague at the expense of the europhile Kenneth Clarke. In 2001 both Clarke and Portillo attracted support from across the ideological spectrum of the parliamentary party, suggesting that a section of the parliamentary party had moved away from ideologically driven voting behaviour. However, Iain Duncan Smith reaching the final ballot was due to the support of an ideologically cohesive group of traditional Thatcherite MPs and indicative of the continued significance of ideology on the direction of the Conservative party.