Cabinet government refers to any government in which most executive power is invested in a cabinet - often the members act with collective responsibility. Traditionally, the United Kingdom has had a cabinet government - if, however, one subscribes to the view that the prime minister has become dominant (as opposed to primus inter pares) and often bypasses cabinet, the United Kingdom has become a country of prime ministerial government. Margaret Thatcher and Tony Blair have both been attributed with the so-called "presidentialisation " of the prime minister due to their extensive use of bilateral meetings , Prime Minister's Office and their authority (from landslide victories).