In September, Truss outlined hefty tax cuts to drive a dramatic increase in British economic growth, which she promised would pay for a rapid increase in government borrowing.

Investors took fright, sparking a fire-sale of British government bonds, amplified by the financial structure of pension funds.

In a parliamentary hearing today, Hunt criticised the foundations of Truss’s plans, the failure of which led to his installation as finance minister and Rishi Sunak as a replacement prime minister.

“In particular I think it’s clear you can’t fund tax cuts through increased borrowing. That is a clear thing that we changed course on,” Hunt said.

A spokesperson for Truss said Hunt, a fellow Conservative, had made mistakes of his own.

“Liz was always clear that you can’t deliver economic growth and thus reduce borrowing by hiking taxes,” the spokesperson said.

“Raising Corporation Tax from 19% to 25% looks like a pretty bad mistake right now when you consider how a firm like AstraZeneca is locating its new plant in Ireland where Corporation Tax is half the rate now being levied by the British government.”

Sunak’s divided Conservative Party sits about 15 to 20 points behind the opposition Labour Party ahead of an expected election next year, according to most opinion polls.