HMRC opened the scheme, which allows employers to apply for grants to cover 80% of an employee’s pay, up to a monthly maximum of £2,500, at 8am today.

During 10 Downing Street’s daily briefing, the chancellor Rishi Sunak said the grants will help businesses pay the wages of more than one million people who would have been at risk of losing their job had they not been furloughed.

Sunak said firms should receive their money within six working days.

Daniel Tomlinson, economist at think tank the Resolution Foundation, said: “The sheer scale of applications for the government’s Job Retention Scheme on its opening day shows just how badly the scheme is needed.

“Without firms having the option to furlough staff, Britain could be facing the prospect of totally unprecedented numbers of people being unemployed. The claims made today alone are set to cost at least £4.2bn if staff are furloughed for three months.”

Analysis published by the Resolution Foundation earlier today suggests more than 11 million Brits could be unemployed or furloughed over the next three months.

As many as 8.3 million people will be furloughed under the government’s Coronavirus Job Retention Scheme, the think tank estimates, while unemployment is expected to rise sharply to 3.4 million by the summer, taking the total number of non-workers to 11.7 million.

What is the Coronavirus Job Retention Scheme?

The government’s Coronavirus Job Retention Scheme is an initiative to prevent mass lay offs during the lockdown. Employers can apply for a government grant to cover 80% of an employee’s pay, up to a monthly maximum of £2,500. These workers are furloughed, which means they remain on their company’s payroll but must not undertake any work for the business.

Chancellor Rishi Sunak said: “Our unprecedented job retention scheme will protect millions of jobs across the country and is now up and running.

“It’s vital that our economy gets up and running again as soon as it’s safe – and this scheme will allow that to happen.”

The scheme was originally set to last until 1 June, but the government last week extended it for another month until the end of June.

Read our guide on what it means to be furloughed here