The International Monetary Fund warned that the measures are likely to fuel the cost-of-living crisis, and that the UK government should reconsider its plan for tax cuts.
The International Monetary Fund said the proposal would add to pressures pushing up prices, as well as increase inequality.
The IMF said it understood the package aimed at boosting growth via tax cuts, but it also said that it could boost inflation, which the central bank of the UK is trying to bring down.
The announcement caused days of financial turmoil, as investors dumped the pound and UK debt, and some of the country's biggest lenders suspended mortgage deals because of the uncertainty.
This is an extremely blunt warning from the IMF, indicating that Kwasi Kawarteng's 45 bn mini-Budget spree may not only have been ill-judged and risks sharper rate rises, but could also increase income inequality.
The growth plan of the Truss government focuses on tax cuts for the better off in the hope that it will benefit society by boosting investment, innovation and job creation.
A 2020 study by academics at the London School of Economics examined the impact of such policies over five decades in wealthy countries and found they didn't boost growth or jobs. The study claimed that they were more likely to widen the gap between rich and poor.
At the beginning of the Conservative leadership campaign, a top IMF official told me large-scale universal tax cuts in the UK would be a mistake, as the energy price crisis has intensified, so it's been calling for measures that are targeted towards the least well-off. It's openly urging the government to focus on that when the Chancellor announces the next instalment of his plans in November.