Goldman says that the UK should brace for a worse recession than previously thought.
The country's growth forecast was lowered from 0.4% to 1% in a recent research note.
After a week that saw the prime minister scrap her tax cut proposals and then resign as UK leader, they have revised their outlook.
The bank said that most of the tax cuts announced in the mini-budget would be reversed.
As financial conditions tighten and the corporate tax rate increases in April, analysts now think there will be a deeper recession.
After her $48 billion package pushed the British pound to an all-time low against the dollar, she made a U-turn on her tax cut pledges.
The basic rate of income tax was going to be slashed from 19% to 18%, and the corporation tax was going to be raised from 19% to 25%.
The next leader of the UK is expected to stress fiscal responsibility as they fight to be elected.
Goldman says that the abandonment of tax cuts will increase the likelihood of a UK recession.
The UK's inflation hit a four decade high of 10.1% on Wednesday as the Bank of England hiked interest rates. There is a chance that the country will slip into a deep recession.
The UK is expected to suffer an economic decline next year, according to a number of forecasters.
The Bank of England has predicted that the economy will shrink in the next few years.
There was chaos in the markets during the 45 days that Liz Truss was the UK prime minister.