British finance minister Rishi Sunak said on Wednesday the government would "do everything we can" to recover COVID-19 emergency business loans stolen by fraudsters that critics have said could run into the billions of pounds.

"I'm not ignoring it, and I'm definitely not 'writing it off,'" Sunak said on Twitter.

A British junior government minister resigned on Monday in protest at what he said were "woeful" efforts to stop the fraudulent abuse of coronavirus support schemes.

The government last week disputed reports it had written off 4.3 billion pounds ($5.8 billion) of loans from more than 80 billion pounds of job support, but it acknowledged some fraud had occurred.

Sunak said it was important to remember the context of how the loans were rushed out as British economy was being largely shut down to slow the spread of COVID-19.

"Businesses on the brink of collapse needed support quickly, something that many, including Labour, were calling for," he said, referring to the main opposition Labour Party.

"We delivered that support in record time with furlough and our loan schemes saving thousands of jobs."

He said the government had invested more than 100 million pounds in an anti-fraud taskforce with 1,265 staff, one its largest and quickest ever responses to a fraud risk, with 13,000 one-to-one enquiries opened in 2020/21.

The vast majority of people did the right thing but the government was still addressing incorrect claims, Sunak said.

Last year, it stopped or recovered nearly 2.2 billion pounds in potential fraud from its Bounce Back Loans and 743 million pounds of over-claimed furlough grants, he said.

($1 = 0.7401 pounds)

(Writing by William Schomberg, Editing by Kylie MacLellan and Alistair Smout)