The Prime Minister’s role is huge and varied. It includes chairing the council of ministers and inner cabinet, meeting with the leaders of states and supranational bodies (especially the EU) to promote Britain’s interests. They also oversee the country’s intelligence services and deliver speeches at times of national crisis or mourning. They have overall oversight of government policy, and can request to the sovereign a dissolution of Parliament and a general election.
In a world of competing priorities the Prime Minister is often buffeted by events and can find themselves focusing on things that were not part of their original plan, with the blunder of Suez, the winter of discontent, the poll tax riots or Brexit often becoming defining moments in a premiership. On the other hand, a successful leader can make a significant impact and leave behind a legacy of lasting importance, such as Winston Churchill or Margaret Thatcher.
The Prime Minister is the head of government, which means he chairs the meetings of the inner and council of ministers, consults his ministers and state secretaries and goes over their files. It’s a role that requires a great deal of personal dedication and the ability to think on one’s feet, which is why most prime ministers have assistants to help with the daily work. But even with them, the task is huge and if they are not successful at managing their colleagues they may be forced to step down by a vote of no confidence from Parliament. This has happened to Sidney Holland and Keith Holyoake in the past, and it nearly took down Robert Muldoon in 1980.