Sunak is preparing to announce the government's spending plans for the next year alongside increased long-term infrastructure investment designed to meet an election promise to address decades-old regional imbalances.

But his speech on Wednesday is likely to be overshadowed by official forecasts showing soaring national debt levels caused by a coronavirus pandemic that has forced large sectors of the economy and millions of jobs onto taxpayer-funded life-support.

On Monday, Labour's would-be finance minister Anneliese Dodds will use a Reuters Newsmaker event to call for 30 billion pounds of capital spending, retraining schemes to tackle unemployment, and a clear strategy to help businesses plan.

"Labour would make responsible choices to protect our key workers, secure the economy and recover jobs in every part of the country," Dodds will say, according to advance extracts of her speech.

Dodds, a 42-year-old Scottish former academic, is a key part of new Labour leader Keir Starmer's bid to rebrand the party after five years and two election defeats under the hard-left leadership of Jeremy Corbyn and the big-spending promises of his firebrand finance spokesman John McDonnell.

In her speech, she will accuse Sunak and Prime Minister Boris Johnson of acting too slowly to save jobs and failing to appreciate the value of taxpayers' money, pointing to a highly critical watchdog review of procurement during the pandemic.

Even though Britain is four years away from an election, Labour is seeking to tap into anger at the government's handling of public finances throughout the crisis and to persuade voters that Labour can be trusted on the economy.

Dodds' opposite number Sunak saw his popularity soar when he was spending heavily to prop up the economy, but questions are growing over how wisely that money has been used and how it will be repaid.

"The chancellor's irresponsible choices and unacceptable delays are damaging the economy," Dodds will say. "That's why we're in the grip of a jobs crisis - and it's got Rishi Sunak's name all over it."

(Reporting by William James; Editing by Hugh Lawson)

By William James