Question: Stephen Parkinson is a special adviser to a prime minister who leads which party ?

Context paragraphs:
Lance Price: Lance Price (born 3 September 1958) is a British writer, journalist and political commentator.  He was a journalist for the BBC from 1981 to 1998, then became special adviser to Prime Minister Tony Blair, eventually assuming the role of Director of Communications for the Labour Party, coordinating the Labour Party election campaign of 2001.  He has published three books, and appears regularly on Sky News and the BBC.  On 15 January 2015 Price's publishers, Hodder & Stoughton announced his fourth book: The Modi Effect, to be released on 12 March 2015, detailing the rise of the current Indian Prime Minister, Narendra Modi.

Witold Orłowski: Witold Orłowski (born 1962 in Łódź) is a Polish professor of economics.  He is Director of the Warsaw University of Technology Business School and a Member of the Prime Minister’s Economic Council.  Beside, he acts as Chief Economic Adviser for PricewaterhouseCoopers in Poland.  In 2011 he was appointed Special Adviser (budget) to the European Commission.  Currently, he is the Rector of Vistula Group of Universities.  http://www.vistula.edu.pl/en

Nick Butler: Nick Butler is a Visiting Professor at King's College London.  He is a Senior Adviser to Coller Capital, Linton Capital and Corporate Value Associates.  From 2007 to 2009 he was Chairman of the Cambridge Centre for Energy Studies.  He was a special adviser to the former British Prime Minister Gordon Brown from 2009-2010.  He is a non executive Director of Cambridge Econometrics and a Trustee of Asia House.  He is a regular contributor to the Financial Times.

Stephen Parkinson (adviser): Stephen Parkinson (born 1983) is a special adviser to British Prime Minister Theresa May, former think tank researcher, and former lobbyist.

Damian McBride: Damian McBride is a British political advisor.  He is a former Whitehall civil servant and former special adviser to British Prime Minister Gordon Brown.  McBride began his civil service career at HM Customs and Excise.  He worked with Customs and Excise and later became Head of Communications at the UK Treasury, before becoming a special adviser.

Theresa May: Theresa Mary May ( , "née" Brasier ; born 1 October 1956) is a British politician who has served as Prime Minister of the United Kingdom and Leader of the Conservative Party since 2016, the second woman to hold both positions, the first being Margaret Thatcher.  She has been the Member of Parliament (MP) for Maidenhead since 1997.  Ideologically, she identifies herself as a one-nation conservative.

Deepak Vohra: Deepak Vohra is an Indian diplomat, serving as Additional Secretary in the Ministry of External Affairs.  He was the Ambassador of India to Poland.  Deepak Vohra is currently Special Adviser to the Prime Minister of Lesotho and Guinea-Bissau.  In 2012 he was Advisor to the Government of South Sudan.  During his service in the Indian Foreign Service, he has served in France, Tunisia, United States, Chad, Cameroon, Papua New Guinea, Spain, Armenia, Sudan, Poland in 1995 he was deputy high commissioner in Kuala Lumpur.  Prior to his role in Diplomacy, he was an officer on special duty to the Technology Advisor to the Prime Minister of India.  Mr Vohra has also previously worked with Sulabh International and has been a part of United Nations assignments in Africa.  Ambassador Vohra brings extensive insight and expertise on matters of development in developing countries and an understanding of political mechanics in Africa.  He is an Alumnus of St. Stephen's College, Delhi - National Defence College (India) and University of Paris.  A number of unidentified Security and Customs Officers deployed at Juba International Airport have been accused of harassing a senior diplomat on Thursday.  Ambassador Deepak Vohra inaugurated Apati War Memorial at Kargil.

Roger Liddle, Baron Liddle: Roger John Liddle, Baron Liddle (born 14 June 1947) is a British political adviser and consultant who is principally known for being Special Adviser on European matters to the former Prime Minister Tony Blair, and President of the European Commission, José Manuel Barroso.  He also worked together with Peter Mandelson on books outlining the political philosophy of the Labour Party under Blair's leadership.  He is chairperson of the international think tank Policy Network and Pro-Chancellor of the University of Lancaster.

Timo Laaninen: Timo Laaninen is the party secretary of the Centre Party in Finland since 12 June 2010.  Laaninen has been the editor-in-chief of Suomenmaa party newspaper from January 2008.  Before that he has been a political secretary (special adviser) in Esko Aho's cabinet to the minister of internal affairs, Mauri Pekkarinen, minister for foreign affairs Heikki Haavisto and prime minister Esko Aho.  In Anneli Jäätteenmäki's cabinet he was a political secretary for prime minister Anneli Jäätteenmäki and later also for Matti Vanhanen in Matti Vanhanen's cabinet.

Nick Seddon: Nick Seddon MBE (b.1979) is a British political policy adviser, businessman, and author.  He served as a senior special adviser to Prime Minister David Cameron from May 2013 to 2016.  Seddon was educated at Magdalene College, Cambridge.

Supporting paragraphs: Stephen Parkinson (adviser) Theresa May
Answer: the Conservative Party