The Conservatives must reconnect with voters who rallied to the party under Margaret Thatcher, former Cabinet minister Liam Fox will say on Friday.
Dr Fox, seen as a standard bearer of the Tory right, will call for the party to fight the next general election on a radical Thatcherite platform of tax cuts, privatisation and deregulation.
In a speech to business leaders in Birmingham, he will argue the party can win an overall majority in 2015 provided it shows "political courage" and "intellectual creativity".
Following the events surrounding the death of Baroness Thatcher, he will say the Conservatives had lost touch with many of the people who had voted for her.
"Many people in this country will also have been reminded why they were drawn to the Conservative cause under Margaret Thatcher's leadership," he will say.
"Their values have not changed and neither have ours but we are currently lacking the language to reconnect with them. We are their natural home and they are our natural supporters regardless of what background or part of the country they come."
Although he does not directly criticise David Cameron, his speech will be seen as offering the party a radical alternative vision for the next election.
Despite the reforms of the coalition, he will say the country remained "over-taxed, over-regulated" and still spent too much and borrowed too much.
The Conservatives now need to come forward with a programme which rewarded risk-takers and fostered a climate where wealth creation was encouraged.
He will call for a public spending freeze for at least three years, and a "systematic switching" of universal benefits into tax cuts.
There is "instinctive support" among Conservatives, he will say, for reform of inheritance tax, which the Tories promised at the last election but dropped in the coalition negotiations with the Liberal Democrats.
"We must end the iniquitous multi-taxing of the same money," he will say.
"It is not right to tax people's income and then their savings on that income; to tax the movement of assets through capital gains tax and stamp duty, and then tax them again through inheritance tax if they have the audacity to die."
Assets sales he will suggest could include Network Rail, Channel 4, and the Scottish, Welsh and Northern Ireland water industries, as well as the Government's stakes in Royal Bank of Scotland and Lloyds.
There should also be a rethink of the size and structure of Whitehall and the Civil Service, as well as a radical programme of deregulation, he will say.
"I believe it is entirely possible for the Conservative party to win an overall majority at the next general election if we show political courage, intellectual creativity and party unity," he will say.
"Those of us who were drawn to the Conservative Party by Margaret Thatcher's desire to free people from the pigeon holes that they had historically been put into, able to exploit their own talents in a country that valued opportunity, creativity and hard work, have a duty to make that message heard in the next generation as well."
In an apparent side-swipe at Cameron's Old Etonian background, he will emphasise Lady Thatcher's appeal across the class divide, saying that, as the grandson of a miner, it was "unimaginable" that he could have been attracted to the party before she became leader.
"She powered into a meritocratic era, determined to ensure that wealth and ownership were not the preserve of a privileged few," he will say.
Dr Fox will also hit back at UK Independence Party leader Nigel Farage who claimed that Lady Thatcher would have joined his party if she was starting her career now.
He will say that she would have been "horrified" at the thought that Tory voters switching to Ukip could open the door to power to her "mortal enemy", the Labour Party.Suggest a correction