Chancellor Jeremy Hunt, who will unveil the Autumn Statement on Thursday, has warned that everyone will pay more tax under his plans to repair the public finances.
The budget, the government’s second financial package in under two months, comes after mostly now-abandoned tax cuts in the mini-budget, outlined by Liz Truss’s chancellor Kwasi Kwarteng, sparked financial turmoil.
The Treasury has not confirmed details, but the BBC has been told Mr Hunt is set to announce spending cuts of about £35bn and plans to raise £20bn in tax.
The plans are likely to include freezes to income tax bands, and increases to taxes paid on profits made from selling shares and second homes.
Also under consideration is a plan to allow councils to raise council tax by more than 3% without holding a local vote – something they cannot do at the moment.
Mr Sunak has hinted that pensions will rise to keep pace with inflation, telling reporters on the way to Bali that pensioners would be “at the forefront of my mind”.
Asked whether he would heed calls from Tory MPs to protect school budgets, Mr Sunak said he couldn’t comment on specifics ahead of the statement.
But he added: “Even though the situation is difficult […] we will make those decisions balancing everything we have to.
“People can see that yes, the approach we’ve taken is fair, yes the approach we’ve taken is compassionate when considered in the round.
“Taking a step back, the number one challenge we face is inflation,” Mr Sunak added.
“It’s important that we get a grip of that. It’s important we limit the increase in mortgage rates that people are experiencing.”
Tax hikes warning
Thursday’s statement comes amid a worsening economic backdrop, with wages lagging rising prices and the Bank of England warning the UK is facing its longest recession since records began.
Some Conservatives MPs have warned against increasing taxes, with former party leader Iain Duncan Smith warning tax hikes could lead to a “deeper” slowdown.
Sir John Redwood, a former minister on the right of the party, has also warned that “tax rises and the wrong spending cuts now will turn a downturn into a nasty and long recession”.
The government is trying to meet its official fiscal targets, which say debt should be falling and day-to-day spending should be met by tax revenue in three years’ time.
Labour shadow chancellor Rachel Reeves has said she recognises there would be “constraints”, partly because of “mistakes” previously made by the Conservatives.
“Just because you have to make difficult decisions it doesn’t mean you have to make the same decisions,” she said on Sunday.