Factors which influence a PM's relationship with the Cabinet

Factors that affect the relationship and how they have changed

· The management skills of the prime minister some PMs are better at managing the cabinet. A skilled prime minister will exploit the elastic nature of the office to assert control over the Cabinet. The right to appoint and dismiss ministers can be used to reshape the top team, to remove poor performers and bring in new blood, and to marginalise opponents. Patronage

· The prime minister's ability to set the agenda Decisions are rarely, if ever, taken in Cabinet by holding a vote. The prime minister's traditional right to chair the meeting and to sum up at the end is an important source of influence. He or she can also keep certain items off the agenda of Cabinet meetings. Harold Wilson, for example, refused to allow discussion of devaluation of the pound in the period 1964-67, even though several ministers wanted to open up the argument.

· The use of Cabinet committees and informal groups to take decisions Since 1945 prime ministers have made increasing use of Cabinet committees to take decisions, which are later ratified by the full Cabinet. By choosing the membership of these committees, and taking the chair of the most important ones — or placing this responsibility in the hands of a reliable ally —

the prime minister can exercise a significant degree of control. On entering Number 10, Theresa May decided to chair three important committees, including the one dealing with the crucial issue of Britain's exit from the EU. Many decisions are taken in smaller, informal groups, or in bilateral meetings. For example, the market-sensitive decision to place management of interest rates in the hands of the Bank of England was taken by Tony Blair and Gordon Brown within days of the 1997 election victory, and the rest of the Cabinet were informed later. Under the coalition, the presence of two parties in government meant that it was necessary to have more discussion of policy in Cabinet. Yet, even then, an informal body known as 'the Quad' — David Cameron, Nick Clegg and their two most senior colleagues, Chancellor George Osborne and Chief Treasury Secretary Danny Alexander — met regularly to resolve differences between the coalition partners.

· The development of the Prime Minister's Office and the Cabinet Office Although there is no official 'Prime Minister's Department', the prime minister has access to more resources than other ministers, with a Prime Minister's Office in Number 10 Downing Street staffed by a combination of civil servants and special advisers drawn from the governing party. Harold Wilson created the Policy Unit in 1974 to enable the prime minister to gain an overview and to drive policy across departments. Under Blair there was close co-operation between the Prime Minister's Office and the Cabinet Office to support the co-ordination and implementation of policy. The Press Office, which handles the government's presentation in the media, also works closely with the prime minister. Under Blair it gained enhanced importance as part of a newly created Communications and Strategy Directorate in Downing Street. Boris Johnson was seen as too reliant on his adviser Dominic Cummings.

· The impact of the wider political and economic situation It is important to note that the degree to which the prime minister can dominate the Cabinet is affected by a variety of external pressures. A prime minister with a large parliamentary majority and a united party, such as Blair in the wake of the 1997 Labour landslide, will find it much easier to gain ascendancy than one like Major, whose control over the Commons was precarious from 1992 onwards. Popularity with the public, a booming economy and an ability to master events rather than appear as their victim all strengthen the hand of the prime minister in dealing with the Cabinet. Margaret Thatcher's standing improved enormously after victory in the 1982 Falklands War. Gordon Brown was harmed by his decision not to hold a general election on becoming prime minister, after allowing expectations of a contest to build, and his authority was further undermined by the financial crash of 2007-08. Theresa May lost authority when Parliament rejected her deal with the EU over Brexit.