Question: Who was prime minister of the UK from 1955  to 1957 that James Stuart served as Secretary of State for?

<P0-S0> Leonard James Callaghan, Baron Callaghan of Cardiff, {'1': ", '2': ", '3': ", '4': "} (27 March 1912 – 26 March 2005), often known as Jim Callaghan, was a British politician who served as Prime Minister of the United Kingdom from 1976 to 1979 and Leader of the Labour Party from 1976 to 1980. <P0-S1>  Callaghan is to date, the only British politician in history to have served in all four of the "Great Offices of State", having been Chancellor of the Exchequer from 1964–67, Home Secretary from 1967-70, and Foreign Secretary from 1974, until his appointment as Prime Minister in 1976. <P0-S2>  As Prime Minister, he had some successes, but is mainly remembered for the "Winter of Discontent" of 1978–79. <P0-S3>  During a very cold winter, his battle with trade unions led to massive strikes that seriously inconvenienced the public, leading to his defeat in the polls by Conservative leader Margaret Thatcher. <SEP> <P1-S0> Sanjaya Baru is a political commentator and policy analyst, currently serving as Director for Geo-Economics and Strategy at the International Institute of Strategic Studies. <P1-S1>  Penguin India. <P1-S2>  Retrieved on 14 April 2014. <P1-S3> </ref> Previously he had served as associate editor at "The Economic Times" and "The Times of India", and then chief editor at "Business Standard". <P1-S4>  His father B. P. R. Vithal served as Finance and Planning Secretary during former Prime Minister Manmohan Singh's stint as Secretary of Finance. <P1-S5>  Before he became a journalist, he was a member of Communist Party of India (Marxist) when he was a student at University of Hyderabad. <P1-S6>  He became Manmohan Singh's media advisor and chief spokesperson, a role in which he served from May 2004 until August 2008. <P1-S7>  In April 2014, Penguin India published "The Accidental Prime Minister", Baru's tell-all memoir about his time at the Prime Minister's Office (PMO). <P1-S8>  In it, Baru alleges that the prime minister was completely subservient to Congress President Sonia Gandhi, who wielded significant influence in the running of the Singh administration, including the PMO itself. <P1-S9>  The book has sparked off a controversy, with the PMO officially denouncing it as "fiction". <P1-S10>  Baru, however, has said that he set out to show an empathetic portrait of the prime minister. <SEP> <P2-S0>  He was joint-Parliamentary Secretary to the Treasury in Winston Churchill's war-time coalition government and later served as Secretary of State for Scotland under Churchill and then Sir Anthony Eden from 1951 to 1957. <P2-S1> Captain James Gray Stuart, 1st Viscount Stuart of Findhorn, (9 February 1897 – 20 February 1971), styled The Honourable James Stuart between 1909 and 1957, was a Scottish Unionist politician. <P2-S2>  The latter year he was elevated to the peerage as Viscount Stuart of Findhorn. <SEP> <P3-S0> Robert Anthony Eden, 1st Earl of Avon, (12 June 1897 – 14 January 1977) was a British Conservative politician who served three periods as Foreign Secretary and then a relatively brief term as Prime Minister of the United Kingdom from 1955 to 1957.