Comparison: PM & President

The structural differences between the Presidency and the PM seem rather obvious. The US has presidential system where the president is elected independently of the legislature. In the UK the PM is the leader of the largest party in the House of Commons in a Parliamentary System. This make all the difference. The president is elected by the people, through the Electoral College, for a maximum of two terms. The president is entirely separate from the legislature and often has never been a member of it. The president’s cabinet is no more than an optional advisory group and has no decision-making powers.

In the UK, the office of prime minister is the first among equals with executive power divided between the prime minister and cabinet. The prime minister is not directly elected to the office and there is no limit on the length of time he or she may serve. The prime minister gains that office only by being the leader of the largest party in the House of Commons.  The prime minister and cabinet together form a plural executive which is why the prime minister is described as ‘first among equals’. Therefore the UK has 'Cabinet Government' - the government being comprised of the PM and the Cabinet but in the USA the government is the president- the cabinet is there to assist and advise but they do not share power. The president’s cabinet  exists as part of a singular executive. When the president sits alone in a room, the the supreme executive authority is present- this is only true in the UK when the PM sits with his cabinet. All executive power is vested in the president, none in the cabinet. The president  does not have  an entirely free hand in appointing cabinet officers, as they must be approved by a majority vote in the Senate.

US president

UK prime minister


■ When the president proposes legislation to Congress in the State of the Union Address, it is really no more than a wish list. But at least it is the president’s own speech. The British prime minister gets to write the speech but it is delivered by the monarch in what today is called the Queen’s Speech. But it’s a lot more than a wish list. It is the government’s ‘to do’ list for the coming year — a list of near certainties. Clearly the two offices are affected by the separation of powers structure in the United States and the fusion of powers structure in the United Kingdom.

■ Both the president and prime minister may submit their annual budgets to their respective legislatures. But in the United States this marks only the beginning of many months of bargaining during which the president may be defeated on many items. In the UK, the budget submitted is to all intents and purposes the budget that will be passed.

■ Both the president and the prime minister fulfil the role of chief executive — though the president does so as part of a singular executive, while the prime minister is, in theory at least, part of a collective executive. Again, structural differences mean differences of political outcome.

■ Both also get to appoint numerous executive branch officials, but unlike the president, the prime minister does not require anyone to confirm those appointments before they take effect. The British prime minister lacks some significant powers that the American president enjoys, and most of them are performed by the monarch:

■ The president can sign and veto legislation. In Britain that is the power of the monarch, though a monarch has not refused to sign a bill passed by Parliament since 1707 — 80 years before the US Constitution was conceived. The president appoints all federal judges, but in Britain the power to appoint judges was given in 2006 to the independent Judicial Appointments Commission.

■ The president has the power of pardon — a power reserved to the monarch in Britain.

■ Most importantly, the president is not only chief executive (head of government) but also head of state. In Britain the two roles are separated with the monarch fulfilling the head of state role. However, the prime minister enjoys certain roles and powers of their own:

■ Prime ministers play an important role in Parliament and none more so than in answering questions at their weekly half-hour Question Time. A prime minister’s ability to ‘stand and deliver’ at Prime Minister’s Question Time is vital to their survival. Presidents face no such ordeal.

■ Prime ministers also make occasional statements to Parliament, appear before the Commons’ Liaison Committee and occasionally lead in significant parliamentary debates. Again, the American president plays none of the equivalent roles.

■ The prime minister’s patronage also extends beyond executive branch appointments to such posts as the chairmanship of the BBC and Church of England bishops and archbishops, and recommending life peerages.


The president has no formal links with Congress. Indeed, his party may be in the minority in one or both houses. But the president’s continuance in office does not rely on him winning votes in Congress. There are no votes of confidence that could abruptly bring his administration to an end and precipitate new elections. Even were the president to be impeached, found guilty and removed from office, the vice president would step up and take over. The president lacks both the sticks and carrots that the British prime minister enjoys in controlling the legislature. Congress possesses some significant checks on the president. It can:

■ amend, block or reject the bills and budgets he proposes

■ override the presidential veto

■ reject appointments to the executive and the judiciary (Senate)

■ reject treaties (Senate)

It also possesses powers to hold the president accountable through investigation and impeachment of any executive branch official, including the president.

However, the prime minister are subject to checks and scrutiny by Parliament . The Prime ministers’ survival depends on both their maintaining their leadership position and their party maintaining its majority status.  Parliament can  scrutinise and check the actions of the executive. It can hold the prime minister and government to account through: Question Time; select committees; policy debates; early day motions; and votes of no confidence. 

So while a president might dream of having the kind of dominance over Congress which a Pm has over Parliament they probably don't envy the ordeal of PMQs and the constant necessity to beware rivals and rebels within their party. Theresa May's experience as PM is unlikely to serve as an example of prime ministerial dominance.

The structural difference identified above result in the most stark contrast when it come to the cabinet.  Illustrated by the famous occasion when President Lincoln took a vote in his cabinet in which he was in a minority of one. He promptly declared his vote to have won since after all he is the government. When the president is alone in a room - the whole executive could be said to be in that room. This means the culture of the core executive is quite different in the UK and USA. The cabinet is not the president's most useful tool, he is likely to depend far more closely on his advisers chosen without Senate approval in the Executive Office and White House Office. This inner circle has much more of the culture of a court where having the ear of the president is the source of the only real influence. In this inner circle the Chief of Staff acts as enforcer, gate keeper and trusted adviser. It is also a place where the president can be surrounded by people he trusts and has know for many years- even members of his family.

Traditionally Cabinet Government in the UK operated quite differently with the Cabinet, Cabinet Committees and the Cabinet Office providing the PM with the means of exerting control over the machinery of government, but there has been a steady increase in the number and importance of SPADs or special advisers who form a kind of Number 10 machine to the extent that comparisons are made with the White House in an on going debate about the extent of presidentialism in the role of the PM. However, the PMs cabinet are colleagues and  rivals as well essential to the concept of collective responsibility. Trump's sacking of cabinet secretaries who displeased him was accomplished with no thought that they might go on to take his job, but this is always a consideration for a PM. As the resignation of Geoffrey Howe led to her fall from power and John Major's admission that his cabinet contained minsters he considered to be 'bastards' show a culture of rivalry and necessity to chose cabinet appointments with care that is alien to a US president. The rational choice model is useful in understanding appointments to the cabinet as neutralising rivals and satisfying party factions are matters of PM survival.  Theresa May's appointment of Boris Johnson to her cabinet must have been accomplished through gritted teeth.

The president can nominate anyone to be in his cabinet as long as he feels they will be given Senate approval. Serving members of the legislature barred from serving in the cabinet but can always resign first. President decides frequency and regularity of meetings which tend to become fewer and more infrequent during the president's time in office. Cabinet members are mostly recruited for their policy specialisation: rarely do they move to a different department. Cabinet members are often strangers to the president. He or she arrive in office with no shadow cabinet and Cabinet meetings are often the only time some cabinet members see the president. However in the UK membership exclusive to members of Parliament. Prime ministers are obliged to maintain frequency and regularity of meetings and  Cabinet members are usually policy generalists: hence cabinet reshuffles.

No prime minister could ignore the collective will of the cabinet the way an American president can, and hope to survive in office for very long.  Both PM and President will find their office is shaped  circumstances and their own personality.  Although the structures are quite different both offices allow for considerable flexibility and the opportunity to shape it or fail to mange it. From Trump's chaotic White House to Reagan's afternoon naps or Carters workaholic schedule or Blair's control freakery  or Thatcher's iron lady, the  view of both office have been seen as presidential , imperial or imperilled. The concept of the imperial presidency dates from the early 1970s, and in Britain Lord Hailsham popularised the phrase ‘the elective dictatorship’ in 1976. The concepts of ‘presidential government’ and ‘prime ministerial government’ gave way to the ‘imperilled presidency’. And the idea of the British prime minister as an elective dictator seemed less convincing following the demise of Margaret Thatcher in 1990, and also of David Cameron or Theresa May. 

Edexcel Question 2 (comparative Paper 3 2022)

Analyse how the US President could be considered to be less effective than the UK Prime Minister in achieving their legislative goals.

For students taking the Edexcel exam, this question should be quite straightforward. It is only worth 12 marks so  20 minutes should suffice. 

THERE ARE NO AO3 MARKS. So there's no need to 'answer' the question by agreeing or disagreeing. Simply explain how US presidents find getting their legislative proposals through Congress harder than UK PMs find getting theirs through Parliament.

The structural comparative theory is useful in understanding how US presidents find achieving thier legislative programme harder than UK PMs because of the difference in the structure of the respective constitutions. The fusion of powers in the UK and the separation of powers in the US,  Since the legislative and executive branches of the constitution are fused this allows UK PMs to  use patronage, and makes the UK Prime Minister more effective at directly influencing individual members of Parliament than the US President over Congress 


The rational comparative theory is useful because UK Prime Ministers are the leaders of the biggest party in Parliament, whereas the US President is an elected figurehead who may not have the same broad party support from elected officials which means it is in the rational self-interest for UK MPs who are in the government party to support the PM's legislative programme since this will make promotion to the government through patronage more likely. The US president has no ability to exert influence on Congress through patronage.


The cultural comparative theory is useful in explaining how UK PMs find achieving their legislative programme easier than US presidents since there is an expectation that MPs will act according to a mandate model of representation. An MP's party identity is much more likely to be stronger in the UK than for members of Congress who are likely to see their role as akin to the trustee model. This means that there tends to be broader support within the UK Parliament for the Prime Minister’s policy proposals amongst their own MPs in particular, whereas the US President must negotiate more with individual members of Congress and party leaders within each chamber 


Recent examples: 

Rishi Sunak's Rwanda Bill which ultimately passed easily after pressure from the whips. Biden's funding for Ukraine was stalled in the House of Representatives.