David Cameron

U.S. President Barack Obama and British Prime Minister David Cameron, left, watch a flypast on the second day of a NATO summit at the Celtic Manor Resort in Newport, Wales on Friday, Sept. 5, 2014.

Matt Dunham/AP

U.S. President Barack Obama and British Prime Minister David Cameron, watch a flypast on the second day of a NATO summit at the Celtic Manor Resort in Newport, Wales on Friday

David Cameron Visits The Shetland Islands...LERWICK, UNITED KINGDOM - JULY 23:  Prime Minister David Cameron is seen as he is taken out to sea on the fishing boat, 'Radiant Star' from Lerwick captained by Victor Laurenson (not pictured) who showed the Prime Minister how to steer the vessel on July 23, 2014 in Scalloway, Sheltand Islands. It is the first time Shetland has seen a prime minister visit in 34 years, following the visit of Margaret Thatcher in 1980. (Photo by Stefan Rousseau - WPA Pool/Getty Iages)

Stefan Rousseau/Pool/Getty

Prime Minister David Cameron is the first prime minister to visit the Shetland Islands in 34 years, following the visit of Margaret Thatcher in 1980. He rode on the fishing boat ‘Radiant Star’ in the Scalloway area of the islands.

Jean-Claude Juncker receives David Cameron, British Prime Minister...epa04319307 A handout photograph made available by the European Commission showing new president of the European Commission Jean-Claude Juncker (R) receiving British Prime Minister, David Cameron as EU leaders met in Brussels, Belgium, 17 July 2014.  Jean-Claude Juncker, confirmed by the European Parliament on 15 July 2014 as the next European Commission president with only David Cameron and Hungary's Prime Minister Viktor Orban. EU leaders failed on 16 July 2014 to agree on top political appointments, successors need to be found most urgently for EU foreign policy chief Catherine Ashton and President Herman Van Rompuy.  EPA/LIEVEN CREEMERS / EUROPEAN COMMISSION / HANDOUT  HANDOUT EDITORIAL USE ONLY/NO SALES

Lieven Creemers/EPA

A handout photograph made available by the European Commission shows Jean-Claude Juncker and David Cameron giving each other a high five. Read more

David Cameron...Britain's Prime Minister David Cameron looks up during a visit to a construction site in central London, Tuesday, May 27, 2014. Cameron will travel to Brussels later today to meet European counterparts after resounding victories for the far-right in Britain, France and Denmark, and a strong performance by populist or Eurosceptic groups in many other EU countries in European elections. (AP Photo/Andrew Winning, Pool)

Andrew Winning/AP

Britain’s prime minister David Cameron visits a construction site in central London. Mr Cameron will travel to Brussels on Tuesday to meet European counterparts after election victories for the far right in Britain, France and Denmark Read more

British Prime Minister Prime Minister Da...British Prime Minister Prime Minister David Cameron (L) and Mayor of London Boris Johnson wait for a train at Newark station in central England on May 21, 2014, following a visit to the town were they campaigned ahead of the Newark by-election which is due to be held on June 5. Voters also go to the polls in Britain Thursday May 22, 2014, for local council elections in England and Northern Ireland and also for European elections in England, Wales, Scotland and Northern Ireland. AFP PHOTO / STEFAN ROUUSEAU/POOLSTEFAN ROUSSEAU/AFP/Getty Images

Stefan Rousseau/Getty

British prime minister David Cameron and London mayor Boris Johnson wait for a train at Newark station in central England following a visit to the town were they campaigned ahead of the Newark by-election which is to be held on June 5

Budget 2014...A photographer adjusts a camera as media wait outside 11 Downing Street, the official London residence of the Chancellor of the Exchequer, ahead of George Osborne's Budget speech in the House of Commons. PRESS ASSOCIATION Photo. Picture date: Wednesday March 19, 2014. Photo credit should read: Anthony Devlin/PA Wire

Anthony Devlin/PA

Media wait outside 11 Downing Street, the official London residence of the Chancellor of the Exchequer, ahead of George Osborne’s Budget speech in the House of Commons on Wednesday.

PM to press Hollande on EU reform...Prime Minister David Cameron and French President Francois Hollande arrive at The Swan Inn at Swinbrook in Oxfordshire today where they met the landlord, Archie Orr-Ewing (left) and had lunch. PRESS ASSOCIATION Photo. Picture date: Friday January 31, 2014. See PA story POLITICS Hollande.

Stefan Rousseau/PA

UK Prime Minister David Cameron and President François Hollande of France have a chat with Archie Orr-Ewing, landlord of The Swan Inn at Swinbrook in Oxfordshire. The two leaders had lunch at the pub on Friday. Read more

Britain's Prime Minister David Cameron (...Britain's Prime Minister David Cameron (4th L) and Mayor of London Boris Johnson (3rd R) are pictured during a visit to a Crossrail construction site underneath Tottenham Court Road in central London, on January 16, 2014. The Crossrail project, which is expected to be completed in 2018, will link Berkshire, west of London with Essex, east of London.

Ben Stansall/AFP

David Cameron, UK prime minister, and mayor of London Boris Johnson visit a Crossrail construction site underneath Tottenham Court Road in central London. Crossrail, which is expected to start running in 2018, will link Berkshire, west of London, with Essex, east of London. Mr Cameron is pictured fourth from left, Mr Johnson third from the right Read more

British Prime Minister David Cameron Visits China

Feng Li/Getty Images

Chinese premier Li Keqiang and David Cameron, UK prime minister, talk during a signing ceremony inside the Great Hall of the People. Beijing, China.

Leader of the Conservative Party and Prime Minister, David Cameron, delivers his keynote speech to close the conference in Manchester.

Charlie Bibby/FT

Conservative leader and prime minister, David Cameron, delivers his keynote speech to close the party’s annual conference in Manchester on Wednesday.