Theresa May moved to re-unite the nation and the Conservative Party after the divisive EU referendum as she vowed to govern for struggling working class families rather than a “privileged few” on becoming Britain’s second woman prime minister.

Ms May, who backed Remain in the referendum, handed top Cabinet posts to Leave campaigners. She sprung a major surprise by making Boris Johnson her Foreign Secretary – an astonishing comeback by the man who was the front-runner to succeed David Cameron before being pushed out of the Tory leadership race by his fellow Leave campaigner Michael Gove. It is the former Mayor of London’s first Cabinet post, and puts him back on course to eventually become prime minister if he makes a success of it.

David Davis, a Eurosceptic former Europe Minister, landed the key job of “Brexit minister” in charge of negotiating the UK’s exit with the 27 remaining EU countries. Another prominent Leave campaigner, Liam Fox, also won a recall to the Government as an International Trade Secretary.

The reshuffle was designed to reassure Tory MPs that the new Prime Minister would honour her pledge that “Brexit means Brexit.” Some Eurosceptics fear that she might try to avoid the “clean break” with Europe they demand.

But before her first day in Downing Street was over, Ms May was on the phone to European leaders, pledging to establish a "constructive relationship" while reconfirming her commitment to follow through the will of the people as laid out in the referendum.

Philip Hammond moved from the Foreign Office to the Treasury. The man he succeeded as Chancellor, George Osborne, was sacked from the Cabinet – a remarkable fall for a man often seen as Mr Cameron’s most likely successor. Just over a year after they won a general election, Mr Cameron and Mr Osborne are now both in the political wilderness.

Amber Rudd, a prominent Remain campaigner, won a big promotion to Ms May’s previous job as Home Secretary after only 15 months in the Cabinet as Energy Secretary. Michael Fallon kept his job as Defence Secretary.

Speaking outside Downing Street earlier, Ms May promised to lead a One Nation government, boost social mobility and tackle “burning injustice” as she described her mission as “to make Britain a country that works for everyone”.

But the new Prime Minister skated over the daunting challenge that will dominate her first two years in power – clearing up the mess she inherits from Mr Cameron after the Brexit vote and negotiating the EU exit terms. Also at the top of her in-tray will be SNP demands to keep Scotland in the EU after it voted for Remain. Ms May will meet Nicola Sturgeon, Scotland’s First Minister, shortly to discuss SNP calls for a second independence referendum.

Theresa May's Cabinet: Who's in – and who's out? Show all 27 1 /27 Theresa May's Cabinet: Who's in – and who's out? Theresa May's Cabinet: Who's in – and who's out? Andrea Leadsom Andrea Leadsom has been appointed Secretary for Secretary of State for Environment, Food and Rural Affairs Getty Images Theresa May's Cabinet: Who's in – and who's out? Priti Patel Priti Patel has been appointed International Development Secretary PA Theresa May's Cabinet: Who's in – and who's out? Alun Cairns Alun Cairns will stay on as Welsh Secretary Reuters Theresa May's Cabinet: Who's in – and who's out? Karen Bradley Karen Bradley is now Secretary of State for Culture, Media and Sport Rex Theresa May's Cabinet: Who's in – and who's out? Greg Clark Greg Clark has been appointed Secretary of State for Business, Energy and Industrial Strategy PA Theresa May's Cabinet: Who's in – and who's out? James Brokenshire James Brokenshire has been appointed as Secretary of State for Northern Ireland PA Theresa May's Cabinet: Who's in – and who's out? Stephen Crabb Stephen Crabb has resigned as Work and Pensions Secretary PA Theresa May's Cabinet: Who's in – and who's out? Theresa Villiers Theresa Villiers will not return as Northern Ireland Secretary. She was reportedly offered a role by Theresa May, but turned it down, saying it was not one she felt could take on Getty Theresa May's Cabinet: Who's in – and who's out? Chris Grayling Chris Grayling has been appointed Transport Secretary PA Theresa May's Cabinet: Who's in – and who's out? Damien Green Damien Green has been appointed Work and Pensions Secretary Getty Theresa May's Cabinet: Who's in – and who's out? Liz Truss Liz Truss has been appointed Justice Secretary Getty Images Theresa May's Cabinet: Who's in – and who's out? Patrick McLoughlin Patrick McLoughlin who was Transport Secretary has been appointed Tory Party chairman and Chancellor of the Duchy of Lancaster Getty Images Theresa May's Cabinet: Who's in – and who's out? Justine Greening Justine Greening has been appointed as Education Secretary Getty Images Theresa May's Cabinet: Who's in – and who's out? Gavin Williamson Gavin Williamson is to become the new Government Chief Whip Reuters Theresa May's Cabinet: Who's in – and who's out? Jeremy Hunt Jeremy Hunt will continue as Health Secretary Getty Images Theresa May's Cabinet: Who's in – and who's out? Nicky Morgan Nicky Morgan lost her job as Education Secretary Reuters Theresa May's Cabinet: Who's in – and who's out? Michael Gove Michael Gove has been sacked as Justice Secretary Reuters Theresa May's Cabinet: Who's in – and who's out? John Whittingdale John Whittingdale left his job as Culture Secretary EPA Theresa May's Cabinet: Who's in – and who's out? Oliver Letwin Oliver Letwin, the Chancellor for the Duchy of Lancaster, has been sacked from his role in the cabinet PA Theresa May's Cabinet: Who's in – and who's out? Philip Hammond The former Foreign Secretary has been made Chancellor EPA Theresa May's Cabinet: Who's in – and who's out? Boris Johnson Leading Brexit campaigner is given the role of Foreign Secretary Getty Theresa May's Cabinet: Who's in – and who's out? Amber Rudd Leading Remain campaigner takes Theresa May's old job of Home Secretary PA Theresa May's Cabinet: Who's in – and who's out? Michael Fallon Stays as Defence Secretary AP Theresa May's Cabinet: Who's in – and who's out? Liam Fox The former Defence Secretary is named as head of new Department for International Trade PA Theresa May's Cabinet: Who's in – and who's out? David Davis The former shadow Home Secretary and leadership rival to David Cameron is named Secretary of State for Leaving the European Union - aka Brexit minister PA Theresa May's Cabinet: Who's in – and who's out? George Osborne Gone as Chancellor - and fails to secure any new role in May's government GETTY Theresa May's Cabinet: Who's in – and who's out? David Mundell The Conservative Party's only Scottish MP retains his role as Scottish Secretary Getty Images

Ms May said: “My party is the Conservative and Unionist Party and that word unionist is very important to me. It means we believe in the Union, the precious, precious bond between England, Scotland, Wales and Northern Ireland - but it means something else that is just as important. It means we believe in a union not just between the nations of the United Kingdom but between all of our citizens - every one of us - whoever we are and wherever we're from.

"That means fighting against the burning injustice that if you're born poor you will die on average nine years earlier than others. If you're black you are treated more harshly by the criminal justice system than if you're white. If you're a white working class boy you're less likely than anybody else in Britain to go to university. If you're at a state school you're less likely to reach the top professions than if you're educated privately. If you're a woman you will earn less than a man.”

Making clear she had got the message from the EU referendum, Ms May said: “If you're from an ordinary working class family, life is much harder than many people in Westminster realise.” She promised these families: “The Government I lead will be driven, not by the interests of the privileged few but by yours. We will do everything we can to give you more control over your lives.

"When we take the big calls we will think not of the powerful, but you. When we pass new laws we will listen not to the mighty, but to you. When it comes to taxes we will prioritise not the wealthy, but you. When it comes to opportunity we won't entrench the advantages of the fortunate few, we will do everything we can to help anybody, whatever your background, to go as far as your talents will take you.”

Mr Cameron formally tendered his resignation to the Queen after winning a standing ovation in the Commons at his swansong at Prime Minister’s Questions. He urged his successor to keep Britain "as close to the European Union as we can.”