Theresa May is to set out her vision of how the Conservatives can position themselves in "the new centre ground of British politics".
In her first conference speech as Tory leader, the prime minister will denounce the "sanctimonious pretence of moral superiority" of Jeremy Corbyn's Labour and insist her government can be "a force for good".
She will say: "I want to set our party and our country on the path towards the new centre ground of British politics - built on the values of fairness and opportunity - where everyone plays by the same rules and where every single person, regardless of their background or that of their parents, is given the chance to be all they want to be."
Concluding a four-day conference in Birmingham, Mrs May will draw a clear line under the era of her predecessor David Cameron by saying her administration's aim will be to "put the power of government squarely at the service of ordinary working-class people".
Amid a global wave of disillusion with traditional politics, Mrs May will align herself with voters who complain politicians are out of touch.
"Just listen to the way a lot of politicians and commentators talk about the public," she will say. "They find their patriotism distasteful, their concerns about immigration parochial, their views about crime illiberal, their attachment to their job security inconvenient. They find the fact that more than 17 million people voted to leave the European Union simply bewildering."
She will also make a bid to usurp Labour as the party of the NHS, workers and public servants, as well as oppose the "libertarian right" in her own party, which sees the private sector, free markets and competition as the solution to all problems.
Mrs May will say: "It's time to remember the good that government can do. Time for a new approach that says while government does not have all the answers, government can and should be a force for good; that the state exists to provide what individual people, communities and markets cannot; and that we should employ the power of government for the good of the people.
"Time to reject the ideological templates provided by the socialist left and the libertarian right and to embrace a new centre ground in which government steps up - and not back - to act on behalf of the people.
"Providing security from crime, but from ill health and unemployment too. Supporting free markets, but stepping in to repair them when they aren't working as they should. Encouraging business and supporting free trade, but not accepting one set of rules for some and another for everyone else.
"And if we do - if we act to correct unfairness and injustice and put government at the service of ordinary working people - we can build that new united Britain in which everyone plays by the same rules, and in which the powerful and the privileged no longer ignore the interests of the people."