Primus Inter Pares

Primus inter pares is a Latin phrase meaning first among equals. It is typically used as an honorary title for someone who is formally equal to other members of their group but is accorded unofficial respect, traditionally owing to their seniority in office. 

The classic view of Cabinet Government was laid out by Walter Bagehot in The English Constitution (1867) in which he described the prime minister as the primus inter pares ("first among equals").This view was challenged in The British Cabinet by John P. Mackintosh, who instead used the terminology of Prime Ministerial Government to describe the British government. This transformation, according to Mackintosh primarily resulted because of the diminishing role of the Cabinet Ministers and because of centralisation of the party machine and the bureaucracy. Richard Crossman also alluded to the presidentialisation of British politics in the Introduction to the 1963 version of Walter Bagehot's The English Constitution. Crossman mentions the Second World War, and its immediate aftermath as a water-shed moment for Britain that led to immense accumulation of power in the hands of the British prime minister  These powers, according to Crossman, are so immense that their study require the use of presidential parallels.