Unit 6C: Comparative UK and US Politics Alan Dobson Professor at the Department of Politics at the University of Dundee writes for the BBC Parliament

The power and the glory? Prime minister and president

The Executive is that part of government that carries out policy, puts it into effect and executes it.

The British prime minister has traditionally been described, in slightly Orwellian terms, as primus inter pares, or the first among equals.

In fact some are more equal than others, and over the last forty years or so there has been much debate about the PM becoming presidential.

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In other words the PM is far from being equal with his or her ministers, and has the power to set the agenda, can hire and fire members of the Cabinet (though injudicious mass firings can weaken rather than strengthen the position of the prime minister).

He or she employs a growing number of advisers who are responsible directly to her or him.

The PM is also in a highly privileged position for moulding public opinion, takes the role of leading foreign policy at summit meetings, is party leader, and retains the ability to make crucial decisions when departments of state have conflicting advice and agendas.

In the words of Harry S Truman, just as the buck stops in the president's Oval Office so it often stops in the PM's office.

Checks and balances in the USA

In the US Government, the president has no one who could even remotely claim to be an equal, but there are many formal limitations on presidential power and in the words of eminent American scholar Richard Neustadt presidential power may only amount to the power of persuasion.

The president operates within a rigid system of checks and balances which are far more potent than anything in the British system.

The president may be commander in chief of the armed services, but only the Congress can declare war.

The president may have a major legislative programme, but if the Congress is dominated in one or two of its houses by the opposition party implementing such a programme will be extremely difficult.

The US Cabinet is not as strong as the Cabinet in Britain, but it is less easily managed as the departments of state are often staffed with independently minded secretaries with officials who are far more politicised than is the case in the British Civil Service with its tradition of political impartiality.

Similarity: personal advisers

Perhaps the greatest similarity between the British and American Executives in recent years has been the growth of networks of close personal advisers for the prime minister and the president.

The number of staff in the prime minister's office has grown remarkably over the last decades and particularly under Prime Minister Tony Blair.

There is also an accompanying tendency to seek the advice of think tanks to supplement or supersede the advice of conventional civil service sources of information and advice.

In the USA these tendencies are even more pronounced.

The creation of the National Security Council and the development of the position of national security adviser from 1947 onwards and the creation of the National Economic Council in 1993 have created a kind of parallel bureaucracy centred on the White House which often works at odds with the traditional bureaucracy.

It is within this broad context that questions are often posed about how powerful presidents and prime ministers actually are.

Answering such questions is not easy as institutions and procedures continue to develop and change.

Equally important are the characteristics of the individual incumbents.

For example presidents with enormous persuasive powers such as Ronald Reagan and Bill Clinton can be extremely powerful and achieve much.

Presidents like Jimmy Carter and Gerald Ford who lacked persuasive abilities have an up-hill struggle to wield effective power.