A parliamentary or cabinet system of government is a government where all the executive powers of government are vested in a Prime Minister who is the head of government and head of the majority party or ruling party, but is not the head of state. In this system of government, the head of state who exercises only ceremonial functions may be a monarch or president who is the figurehead.

The prime minister and the entire ministers in his cabinet are all members of the same party or coalition of parties. In a cabinet system of government, there is no complete separation of powers, nor a complete fusion of powers. Though the executive and the legislature are completely fused, there is no over-lapping of powers because the same people constitute both arms. The judiciary is completely separate from the legislature and the executive.

Apart from the doctrine of collective ministerial responsibility and the doctrine of individual ministerial responsibility to parliament, the prime minister as head of the government or executive arm has the power to dismiss any minister and he is primarily responsible for the discipline of his cabinet. The stability of the government depends a lot on the ruling party controlling a reasonable majority in the parliament or being able to form a coalition government with another party or parties.

There is an official opposition party in the parliament, which is usually the party having the highest number of votes next to the ruling party in the parliament. The members of the parliament and the executive arm are one. The prime minister is subject to his party and is controlled by the party. He remains in office as long as his party has the majority of members in the parliament. However, when a vote of “no confidence” is passed on him and his cabinet by parliament, the Prime Minister and his entire cabinet is obliged to resign.

The United Kingdom is the origin and home of this system of government. Other countries operating a parliamentary system of government include: Canada, Jamaica, Israel, India, Australia, Lesotho, Ethiopia and so on.