Boris Johnson has pledged a tax cut for high earners in his bid to be the next Tory leader.
The Conservative Party leadership candidate is drawing up plans to raise the 40p income tax threshold to £80,000 at a cost of almost £10 billion.
The higher rate of income tax currently applies on earnings over £50,000 in England and the move could benefit more than three million people.
The former foreign secretary believes the cost of the policy could be met through some of the cash set aside for no-deal Brexit planning.
In his regular Daily Telegraph column, he said: "We should be cutting corporation tax and other business taxes.
"We should be raising thresholds of income tax - so that we help the huge numbers that have been captured in the higher rate by fiscal drag.
"We can go for much greater economic growth - and still be the cleanest, greenest society on earth."
Under the plans someone earning £60,000 is estimated to see their tax bill fall by £1,000, the newspaper reported.
The move will cost an estimated £9.6 billion a year and will be funded from the £26.6 billion of "fiscal headroom" currently set aside by the Treasury for no-deal preparations.
It will also be partly offset by increased National Insurance contributions.
Candidates in the Tory leadership election have until 5pm on Monday to enter the race to become party leader and prime minister.
Theresa May officially stepped down as party leader last week but will remain prime minister until her replacement is found.
Candidates need the backing of eight Conservative MPs to officially enter the race.
Michael Gove is battling to stay in the contest after his admission of cocaine use led to calls to withdraw.
The environment secretary will attempt to present himself as a "serious" alternative Mr Johnson, the contest's frontrunner, when he launches his campaign on Monday and insists he is "undaunted" by criticism.
But he suffered a blow as work and pensions secretary Amber Rudd declared her support for his rival Jeremy Hunt.
And he faced calls to pull out of the contest for Number 10 by former Tory chairwoman Baroness Warsi.
Mr Gove endured a bruising interview on Sunday on BBC's Andrew Marr Show where he was repeatedly questioned about his cocaine use 20 years ago.
At his launch event, Mr Gove will say: "I have led from the front undaunted by criticism and resolute in the need to solve complex issues because that is what our country needs."
In a message to Tory MPs, he will add: "We need a leader who is ready to lead from day one. A leader ready to be prime minister from day one. A leader ready to face the scrutiny of the studio lights."
Mr Gove will say he can both deliver Brexit and "stop Jeremy Corbyn ever getting the keys to Downing Street".
But Lady Warsi said it was "completely inappropriate" for him to remain in the contest to be the next prime minister.
She told Channel 4 News: "This case isn't just about drug taking, it is about trust, it is about hypocrisy of the highest order and it cannot be that we have somebody who is now mired in this issue of trust and hypocrisy feel that it is still appropriate for him to stand as leader of the Conservative Party and a prime minister of this country."