According to Prof. H.J. Laski there is no foreign institution which, "in any basic sense" the American Presidency may be compared. However, as the real executive heads of two countries the American President and the British Prime Minister may be contrasted in respect their functions and powers. Both the US President and the British Prime Minister occupies a unique position not only in their respective political systems
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.
One restriction is imposed by the character of the body itself, which exercises the sovereign power. A sovereign Hindu ruler will never order the slaughtering of cows just as a Muslim ruler will never abolish Islam from the state.
Sovereignty of the British Parliament is an important feature of the British Constitutional system. The struggle between the King and the Parliament was finally decided by the Glorious Revolution of 1688, which was further reinforced by the Act of Settlement (1701).
Constitutional conventions are not recognized by judicial courts. So the question arises: Why are they so scrupulously, obeyed by all concerned? Dicey says that conventions are obeyed because they are so linked up with the laws of the land that their breach will ultimately lead to the breach of the laws.
It is not possible to make a complete list of the conventions of British constitution. The following are some of the important conventions of UK constitution. Conventions Regarding the Queen, Conventions Regarding Cabinet and Conventions Regarding the Parliament
Constitutional conventions are political traditions or constitutional understandings or practices forming an essential part or a constitution, but are not law in the strict sense of term because the courts enforce a law while conventions are not taken notice of by the courts and are not enforced by them.
The UK constitution is a composite of character and statue, of judicial decisions, of common law, of precedents, usages and traditions. It is not one document, but thousands of them. There are several sources of British Constitution.