UK Prime Minister Rishi Sunak is working on an economic plan to cover UK’s budget shortfalls that could lead to tax increases and spending cuts totalling as much as £50 billion ($58 billion) as he wants to build buffers in public finances.

An official familiar with the matter said Sunak and Exchequer Jeremy Hunt wanted more space on top of the UK’s £35 billion financial shortfall so that the plan would have market credibility. Another said spending cuts and an increase in taxes of around £50 billion might be needed, a figure widely reported in British media on Friday.

UK’s new prime minister tries to restore peace in financial markets after his predecessor Liz Truss sparked turmoil during her seven-week term with a massive unfunded tax cut that sent the pound to an all-time low against the dollar.

On Wednesday, Sunak and Hunt delayed their planned economic announcement from October 31 to November 17 to give them more time to make what the prime minister said was the “right decision” to manage the UK economy.

One of the officials said the two held a “sober” meeting on Thursday to discuss their options. They looked at the latest data showing that markets have stabilised recently. However, the UK still faces serious challenges, with economic growth still subdued due to the Covid-19 pandemic and Russia’s invasion of Ukraine.