The House of Commons is the lower chamber of the British Parliament. Its strength is 652. All members of this chamber are elected directly. The tenure of the House of Commons is 5 years but it can be dissolved earlier by the Queen acting on the advice of the Prime Minister. The House of Representatives is the lower chamber of the American Congress. It consists of 438 members who are elected directly by the American voters. Both the House of Commons and the House of Representatives are, therefore, democratic chambers.
The House of Commons is the most important part of the British lawmaking machinery. It is competent to legislate on sail subjects. The House of Lords, cannot act as a barrier against the House of Commons. It can delay ordinary (non-money) Bills passed the House of Commons at the most for one year under the Parliament Act of 1949. The royal veto has gone out of use The British courts have no power of Judicial Review. So, the legislative supremacy of the House of Commons is well established.
On the other hand, the American House of Representatives is a weak legislative body. Its legislative powers are equally shared by the Senate No which originates in the House of Representatives can become law unless it is passed by the Senate also. The Senate is not a mere delaying or revising body like the British House of Lords. Moreover, USA being a federation, the House of Representatives is not competent to legislate on all subjects. Again, the American President can veto laws passed by Congress, though his veto is not absolute. Besides, the legislative power of the House of Representatives is limited by the, system or judicial review that operates in USA. The American Supreme Court can declare laws passed by Congress to be null and void, if they are in clash to any provision of the constitution.
In financial sphere, the British I louse of Commons is all in all. Money Bills must originate in the House of Commons. They can be neither amended nor rejected by the Lords. The House of Lords can delay money Bills passed by the Commons at the most for one month. On the other hand, the House of Representatives is almost on the same footing as the Senate in regard to money Bills. It is true that the House of Representatives has the exclusive power to initiate money bills. But the Senate has the authority to amend money Bill in any way it likes. So this advantage of the House of Representatives over the Senate is not a real one.
Britain has a parliamentary form of government. This type of government implies that the cabinet is responsible to the House of Commons. It can remain in office as long as it enjoys the support of the majority in the House of Commons. Members of the House of Commons can put questions to Ministers and expose their commissions and omissions.
America has a presidential form of government. This type of government is based on the doctrine of "Separation of Powers". Neither the President nor his Secretaries are responsible to the House of Representatives. The President is elected for a period of 4 years. Death and impeachment apart, he cannot be removed from office before the expiry of four years. So far as Secretaries are concerned, they can be dismissed by him and not by the House of Representatives. The Senate has the authority to approve appointments and treaties.
The British House of Commons is a legislative as well as a constituent assembly. It is competent to deal with any measure of constitutional significance in the same manner in which it passes or repeals ordinary laws. On the other hand, the American House of Representatives cannot amend the constitution itself. It can only propose amendments to the constitution and no constitutional proposal is valid unless it is approved by the Senate.