Chancellor Jeremy Hunt will deliver an Autumn Statement on November 17, where he is expected to announce spending cuts to plug a £40billion black hole in the public purse.
Pensioners and benefit claimants should also learn how much their payments will rise by.
To calm jittery markets after Liz Truss’ shambolic premiership Mr Hunt is set to rein in borrowing by squeezing department Budgets.
Downing Street said: “The Prime Minister told Cabinet that economic stability and fiscal sustainability would be at the heart of this Government’s mission.
In his first intervention since being appointed justice secretary last week, Robert Buckland signalled the government was prepared to think again about the use of Alastair Darling’s emergency 50p tax rate for high earners.
It comes as Tory backbenchers have urged the new Prime Minister to use his first Budget statement to pledge significant tax cuts for middle-income earners.
Steve Baker, deputy chairman of the European Research Group of backbench Eurosceptic MPs, has written to Mr Johnson calling for a cut in capital gains tax – currently set at 20 per cent or 28 per cent depending on circumstances – and changes to inheritance tax rules.
In his letter, seen by The Sunday Telegraph, Mr Baker says Theresa May’s decision not to call a snap election in 2017 meant she “missed an opportunity” to enshrine in law her proposed increase in the income tax personal allowance from £11,850 to £12,500 and higher rate threshold from £46,350 up to £50,000.
