Historical rankings of Prime Ministers of the United Kingdom from his second term only. In 2013, a group of academic staff and students at Royal Holloway, University of London, conducted a postal survey of British Members of Parliament, asking them to evaluate the success of post-war British prime ministers. Some 158 MPs replied to the survey, a response rate of 24%. The respondents included 69 Conservatives, 67 Labour MPs, 14 Liberal Democrats and 8 MPs from other parties. The survey used the same question employed in the 2004 and 2010 University of Leeds studies: MPs were asked how successful or unsuccessful they considered each Prime Minister to have been
Prime Minister of the United Kingdom for example, the powers of government were divided equally between the Duke of Newcastle and William Pitt, 1st Earl of Chatham, leading to them both alternatively being described as Prime Minister. Furthermore, many thought that the title "Prime Minister" usurped the Sovereign's constitutional position as "head of the government" and that it was an affront to other ministers because they were all appointed by and equally responsible to the Sovereign. For these reasons there was a reluctance to use the title. Although Walpole is now called the "first" Prime Minister, the title was not commonly used during his tenure. Walpole