Boris Johnson hails the public’s response and says the volunteers will be “absolutely crucial” in the fight against COVID-19.
Sky News understands that more than half a million people have signed up to the NHS volunteer scheme – double the original target which was set on Tuesday.
Some 504,303 have agreed to take part in the initiative,
It comes as the UK spends a second day in lockdown over the coronavirus – and as the number of deaths was confirmed to have risen to 465.
The PM said the country was coping “very well indeed” amidst the “most challenging possible circumstances”.
Mr Johnson said that “never in our history has the government put its arms around people in the way we are doing now to help them get through this time”.
He also said ministers would be examining legal ways of rallying against those profiteering by hiking up prices during the lockdown.
The government has said that a package of measures to support self-employed workers will be set out by the chancellor on Thursday.