The politics of Saint Kitts and Nevis takes place in the framework of a federal parliamentary democracy. Saint Kitts and Nevis is an independent Commonwealth realm with Elizabeth II as its head of state, represented by a governor-general. He acts on the advice of the prime minister, who is the majority party leader in the National Assembly, and who, with a cabinet, conducts affairs of state.
St Kitts and Nevis has a single National Assembly responsible for making laws, and comprising 14 or 15 members depending upon circumstances. 11 of these are directly elected representatives whilst three are senators appointed by the governor-general (two on the advice of the prime minister and the third on the advice of the leader of the opposition). If the attorney general isn't appointed as a senator then he automatically gets a seat as one, increasing the number of senators to four. Of the 11 elected members, eight represent constituencies in St Kitts and the remaining three represent Nevis seats.
The prime minister is appointed from the representatives by the governor-general, who has a constitutional duty to select someone who is likely to command the support of the majority of the representatives. In practice this would normally mean the leader of the majority party or coalition. If there is no suitable candidate, then the governor-general can dissolve the assembly and trigger a general election. Other ministers are also appointed by the governor-general, on the advice of the prime minister (and so effectively by the prime minister). The prime minister can be removed from office by the assembly, or by the governor-general if he feels that the prime minister no longer enjoys the support of the majority of representatives. The assembly is elected every five years unless the governor-general dissolves it before the end of this period, which he may do on the advice of the prime minister.