Since European Union enlargement in 2004 there has been substantial migration from Central and Eastern Europe into the United Kingdom. This thesis focuses upon Polish and Romanian migrants and examines their involvement in the labour market of the UK. It examines the initial labour market experiences of these groups, along with subsequent career mobility, and identifies key influences affecting each. Regarding the former, a comprehensive investigatory framework is adopted which encompasses skill-based, social, structuring, and agency-related factors. Regarding the latter, a theoretical framework which utilises Dual Labour Market, Cultural Capital, and Strength of Weak Ties theories is used. Combined, the theories enable the rationalisation of labour market structure, migrant skill-based competencies, and network-based relationships respectively which holds intuitive appeal to both research concerns. Qualitative methods were used due to the complexity of issues under investigation, with semi-structured interviews yielding the detailed motivation- and experience- based data necessary to perform thematic analysis. Key findings concerning the initial labour market experience focus upon how migrant tolerance of low-skilled work ranges beyond goal-oriented notions of ‘temporariness’ advocated by previous literature, and how network entrenchment in trajectories of low-skilled agency employment is not necessarily guaranteed. Key findings regarding the mobility experience draw upon theory to outline the relative utilities of language, experience, and qualifications as factors conducive or prohibitive to labour market advancement at different points in the occupational hierarchy. Such contributions are significant as they either develop accepted notions as to why migrants tolerate low-skilled work, use resource-based considerations to challenge network entrenchment, or add definitional rigour and chronology to how migrant occupational mobility is defined.