Describing the situation as a “shambles”, Badenoch accused the government of floating the idea of increasing income tax rates only to “U-turn”.
“This is the first Budget to unravel before it’s even been delivered,” she told the House of Commons.
“The chancellor’s cluelessness, I’m afraid, is damaging the economy now.”
Badenoch also highlighted comments from the chancellor in her Budget last year, when Reeves said: “I am keeping every single promise on tax that I made in our manifesto”, adding that she would not extend the freeze on income tax and National Insurance thresholds because this “would hurt working people”.
The Tory leader asked the PM to confirm the government would not break this promise and continue the freeze on income tax thresholds.
But Sir Keir dodged the question, only saying the Budget would focus on cutting NHS waiting lists, debt and the cost-of-living.
“What we won’t do is inflict austerity on the country as they did. What we won’t do is inflict a borrowing spree like [Conservative prime minister] Liz Truss did,” he added.
In response, Badenoch said it was “quite clear” the government was planning to freeze thresholds.
“If [the chancellor] breaks such a clear promise, how can the public trust a word that she says next week?”
