He/she has formal powers inherited by the monarch such as the ability to go to war and more informal powers such as the media. The PM also has constitutional powers for example being able to decide the election date. This essay shall outline some of the powers at the disposal of the PM as well as some of the constraints that can limit the PMs freedom of action. Firstly, ‘The Prime Minister’s role is peculiarly British in two ways. The first is that as the Head of Government, he must control the House of Commons to remain in office.
The fact that the PM is head of government gives him/her considerable power. The PM owes his or her position to the party and must not forget such a connection. He or she will use the powers of leadership to keep the party united, working out compromise solutions as necessary. As leader of the majority party the PM retains support of the parliament. As long as the majority is a workable one, the PM and his or her cabinet colleagues are in a position to persuade the House to adopt party policies.
In this sense a good relationship between the Pm and his or her party is crucial in allowing the freedom of choice for the PM. Secondly, the PM exercises power under the royal prerogative, powers which can be used but are traditionally powers of the crown. Powers relating to the legislature-e. g. ‘the summoning, proroguing and dissolution of parliament; the granting of royal assent to bills; legislating by Order in Council (e. g. in relation to civil service) or by letters patent; creating schemes for conferring benefits upon citizens where Parliament appropriates the necessary finance’.
Powers regarding the armed forces ‘Powers relating to the armed forces e. g. – the Sovereign is commander in chief of the armed forces of the Crown and the control, organisation and disposition of the armed forces are within the prerogative’. Furthermore, ‘the power of appointment and dismissal, can be, and is, used by the Prime Minister to shape the general and specific direction of policy, as Margaret Thatcher demonstrated in September 1981 when she reinforced her Governments commitment to its economic policy by dismissing several so called wets.
Thirdly, the PM determines the date of the next general election. The PM alone decides when to ask the monarch when to dissolve parliament and therefore the time of the polling day. Normally this will be after four years in office. The PM will choose a time when victory looks most likely, his or her choice may be influenced by party performance in the polls, opinion polls and also by-elections, there are a number of various influences that cast the deciding factor into when election Day is.
On the other hand, a constraint on the powers of the PM could be his/her cabinet colleagues. It clearly limits the freedom of action for any PM. No PM can survive long without the support of his or her cabinet colleagues. The fall of Margaret Thatcher in 1990 is often said to be largely the work of her cabinet, ‘the introduction of the Community Charge for local government sounded the death knell for Thatcherism’ And her presidential style of leadership were making her unpopular. In 1990 there was a challenge to her leadership.
Michael Heseltine stood against thatcher in a challenge to her leadership but ‘despite being only four votes short of outright victory, she stepped down after advice from her Cabinet’. fewer votes than she did but enough to damage her authority to such an extent that in a succession of face to face interviews her cabinet colleagues convinced her not to stand in the second round, thus leaving the way open for john major to be elected. Thatcher was therefore removed from office largely due to the work of her cabinet colleagues.
John Major also had some difficulties in his second ministry with some of his cabinet particularly John Redwood and Michael Portillo, because of their underhand opposition to his policy. Brown enjoyed the advantage of being able to reshuffle his cabinet thoroughly when he took over as PM, hence ensuring the exclusion of his enemies and rivals. He made sure to include some of his ‘inner circle’ including Ed Balls sometimes named Mr Browns ‘representative on earth’  A second constraint on the powers of the PM is the support of the media or lack of it.
If a PM is to be popular and hence successful, he or she needs the support of a large section of the media; this usually itself can be dependent on the popularity of the PM. The Murdoch press is often credited, especially by the newspapers themselves as having more influence than they really have, a Guardian article affirms ‘ Rupert Murdoch's spell is broken. But not his baleful influence’. Moreover when they transferred their support from Major to Blair in the mid-1990s/ it was certainly harmful to Major’s electoral success.
However, if Major had still been popular in the country, it is unlikely that the sun and the times would have switches sides as they did. Brown initially enjoyed a favourable press, largely due to the novelty factor. ‘By the skilful and sustained use of propaganda, one can make a people see even heaven as hell or an extremely wretched life as paradise’ Adolf Hitler’s remarks about the media make the impression that the correct use of it can prove a powerful thing. But by contrast we have seen that when the media turns against the PM it can be a constraint on the power of the PM.
Finally, the size of the majority in the commons can have a substantial effect on the PMs ability to push things through. Tony Blair enters Downing Street on a wave of goodwill after a landslide election victory, his Commons majority of 179 ending 18 years of Conservative rule. Tony Blair was fortunate between 1997 and 2005 with two large majorities. This was an important factor in his success, and his ability and his government’s ability to get programs passed in parliament.
However, it is arguable that because his majority was so huge, some dissidents on the backbench were more willing to cause trouble than they otherwise would have been. In 2993-5, there were a number of Labour backbench revolts which greatly reduced the government’s theoretical majority in the commons. So perhaps it is better to have a large, rather than enormous majority. But governments with small majorities such as Wilson and Callaghan in the period 1974-0 and then John Major in 1992-7 can suffer considerably in the event of a backbench revolt.
Over Europe, Major had great problems within his own party and only managed to ratify the Maastricht Treaty with a majority of one vote because of a backbench revolt. This sort of difficulty undermines the PMs Authority more generally, in the media and among the voters as a whole. Blair found this out for himself in his third term, with a reduced majority, and his first defeat in 2005 on the terrorism bill. Brown of course inherited this slimmer majority from Blair and in March 2008 he faced back-bench rebellions over his counter terrorism bill.
In conclusion, it has been argued that the PM has acted beyond the constitutional role which is primus inter pares (first among equals). The PM can exercise powers held by the crown or prerogative powers for example the ability to go to war. Also the PM decides the election date. But most importantly, he or she is leader of government and by definition the most powerful politician in the country. However, should the PM forget the connection established between the press, the people and his or her party the PM will find it hard to succeed as Margaret thatcher’s downfall highlighted.