UK finance minister Rishi Sunak announced a long-awaited income-support scheme for self-employed people in Britain on Thursday, calling it "one of the most generous in the world" in response to the outbreak of COVID-19.

The British government will pay grants to self-employed people who have lost their livelihood because of the coronavirus lockdown, further extending an unprecedented package of measures to prevent the economy from collapsing.

Sunak, who had previously announced the state would pay 80 percent of the wages of employees to dissuade their firms from laying them off, had come under pressure to offer a similar lifeline to Britain's five million self-employed workers.

He said the government would pay those self-employed people who have been adversely affected by the coronavirus a taxable grant worth 80 percent of their average monthly profits over the last three years, up to 2,500 pounds ($3,000) a month.

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"Our expectation is that this will be up and running by the middle of June," Sunak said during a news conference in Downing Street. 

Despite the measures being welcomed by many in the UK, journalists questioned Sunak on what provisions there would be to protect self-employed people while they waited until June to receive the grant, with Universal Credit payments – the UK's regular scheme for supporting the unemployed – taking up to five weeks. 

The scheme, designed to cover 95 percent of those who make most of their income from self-employment, will be open to those with trading profits of up to 50,000 pounds, for at least three months.

The cap of 2,500 pounds per month is the same as the one for employees in the package of measures announced previously.

"What we have done will, I believe, stand as one of the most significant economic interventions at any point in the history of the British state and by any government anywhere in the world," Sunak said.