How has the Prime Minister's power grown and been limited

It has been argued that the PM's power has steadily grown because:

• The cabinet is no longer the main policy making centre of govt, as the PM now holds this position. 
• The PM is presented as the main spokesperson for the govt, showing that the govt is seen through one individual.
• There is now an extensive 'machine' of policy advice given to the PM, instead of the govt as a whole. 
• Before, the PM would consult the cabinet as a whole, but since the 90s, PMs have increasingly consulted individual ministers, political advisors, think tanks and policy units. 
• The PM has prerogative powers, at the centre of the political stage, due to the growing importance of foreign policy, since the UK joined the EC and after the Cold War. 

However, on the other hand, Prime Ministerial power has certain constraints which include:

• The PM can be sometimes overruled by the Cabinet.
• The PM could be overwhelmed by uncontrolled events, that could potentially remove them from power, or lose support.
  • E.g. Thatcher faced an economic depression at the end of her role as PM. 
  • E.g. Major also faced economic problems. 
  • E.g. Blair suffered huge opposition to the Iraq war (he didn't consult the HOC).
  • E.g. Brown's financial system crashed (credit crash), in 2008.
• The PM can be defeated by Parliament, such as through a no vote of confidence (James Callaghan).
• The loss of public confidence can be catastrophic, as Brown saw. 
• PM can lose power, if they do not have a dominant majority in the HOC (Cameron).
• Under a coalition, the PM must share pwower with their coalition partner (Cameron and Clegg).