In comments addressed to ordinary Britons, she spoke of the ’burning injustice’ suffered by large sections of society: poor people facing shorter life expectancy, blacks treated more harshly by the criminal justice system, women earning less than men, the mentally ill and young people struggling to buy homes.

Acknowledging the struggles faced by many people, May declared: “The government I lead will be driven not be the interests of the privileged few, but by yours. We will do everything we can to give you more control over your lives.”

May appointed David Davis, a former junior foreign minister and strong Brexit advocate, to lead the country’s negotiations for exiting the European Union, her office said in a statement on Wednesday.

Davis, a senior Conservative lawmaker who was beaten by former prime minister David Cameron in the party’s 2005 leadership election contest, was appointed to the newly-created role of Secretary of State for Exiting the European Union.

He will take on the crucial role of securing Britain’s economic security whilst unpicking over four decades of trade, legal and diplomatic ties to the EU.

At the heart of the job will be finding an answer to the key negotiating question: how can Britain keep access to the EU’s single market whilst winning the right to restrict free movement of workers from within the EU?

“Once the European nations realise that we are not going to budge on control of our borders, they will want to talk, in their own interest,” he said on Monday in an article for Conservative grassroots website Conservative Home.

Davis also said Britain should take its time before triggering the formal Article 50 exit process, but could be ready to do so by the start of 2017.

“The negotiating strategy has to be properly designed, and there is some serious consultation to be done first,” Davis said. “This whole process should be completed to allow triggering of Article 50 before or by the beginning of next year.”

May, 59 assumed office after an audience with Queen Elizabeth. An official photograph showed her curtseying and shaking hands with the smiling monarch, for whom she is the 13th prime minister in a line that started with Winston Churchill.

She is also Britain’s second female head of government after Margaret Thatcher.

Philip Hammond was appointed chancellor of the exchequer and Boris Johnson foreign secretary as May swiftly filled up the top posts in her cabinet on her first evening as prime minister.

Hammond, who was foreign secretary, was the first to be appointed and replaces George Osborne, who was fired from the government, Downing Street announced.

The second major appointment – and a much more unexpected one – was Johnson as foreign secretary.

The former mayor of London played a major role in the leave camp during the EU referendum, and was the initial favourite to succeed Cameron, only for his leadership bid to end abruptly when his key Brexit ally, Michael Gove, stood against him.

The final major appointment saw Amber Rudd, the former energy secretary, promoted to home secretary in place of May herself, having only entered parliament in 2010.

Johnson said nothing to reporters as he left Downing Street to head for the Foreign Office. After Hammond left, he made the short trip to the Treasury, to meet his new team. Downing Street said more jobs would be announced soon.

Liam Fox, who left the post of defence secretary in 2011 following revelations that his close friend the lobbyist Adam Werritty had travelled with him on official business, was made secretary of a new ministry for international trade.

Cameron said he was leaving the country stronger and better off than he had found it and wished his successor luck in her negotiations for Britain leave the European Union — the issue that caused his demise.

Earlier on Wednesday, Cameron made his final appearance as prime minister in Parliament, turning the usually raucous prime minister’s questions session into a time for praise, thanks, gentle ribbing, cheers — and a sprinkle of criticism.

The warmth in the House of Commons culminated in loud applause and a standing ovation from his Conservative colleagues for Cameron, 49, who resigned after voters rejected his advice and decided to leave the European Union.

“I will miss the roar of the crowd. I will miss the barbs from the opposition,” Cameron said, promising to watch future exchanges as a regular Conservative lawmaker on the back benches.

He even poked fun at himself, reminding legislators of a barb he directed at then-Prime Minister Tony Blair more than a decade ago: “He was the future once.”

May must try to limit the damage to British trade and investment as she renegotiates the country’s ties with its 27 EU partners. She will also attempt to unite a divided ruling Conservative party and a fractured nation in which many, on the evidence of the vote, feel angry with the political elite and left behind by the forces of globalisation.

EU leaders, keen to move forward after the shock of ’Brexit’, want May to launch formal divorce proceedings as soon as possible to help resolve the uncertainty.

But she has said the process should not be launched before the end of year, to give time for Britain to draw up its negotiating strategy.

Although she favoured Britain remaining in Europe, May has repeatedly declared that “Brexit means Brexit” and that there can be no attempt to reverse the referendum outcome.

The shock vote partly reflected discontent with EU rules on freedom of movement that have contributed to record-high immigration - an issue on which May, as interior minister for the past six years, is politically vulnerable.

But EU leaders have made clear that free movement is a fundamental principle that goes hand-in-hand with access to the bloc’s tariff-free single market, a stance that will hugely complicate May’s task in hammering out new terms of trade.

May is seen by her supporters as a safe pair of hands to steer the country through the disruptive Brexit process. Colleagues describe her as cautious, unflappable and intensely private.

“I think around the cabinet table yesterday the feeling was that we have our Angela Merkel,” said Jeremy Hunt, health secretary in Cameron’s team which met for the last time on Tuesday.

“We have an incredibly tough, shrewd, determined and principled person to lead those negotiations for Britain,” Hunt told Sky News television.

German Chancellor Merkel will be May’s most important counterpart on the continent as the process unfolds. Both women are renowned for their firmness, pragmatism and discipline.

Tony Travers of the London School of Economics said May would likely not rush to trigger Article 50 of the EU constitution, which starts a two-year countdown to a final exit.

“I don’t detect Theresa May being an impulsive person,” Travers said. “I think she’s a cautious person, and the British political establishment needs to come to terms with this massive decision.”

With additional reporting from the Guardian