Amid suggestions that the restrictions will have to remain in place until June – much longer than the three weeks announced – the cabinet office minister signalled a likely extension.
“I can’t make an accurate prediction,” he said, urging “everyone” to keep “making a sacrifice”.
Mr Gove also refused to back scientists who have suggested the peak of the outbreak will now be in mid-April, rather than late May or early June as originally expected.
“The date of the peak depends on all of our behaviour – it’s not a fixed date in the calendar like Easter,” he told the BBC’s Andrew Marr programme.
And he defended the government’s record on testing for the virus, as the daily total hit the target of 10,000 – still a fraction of the 500,000 tested each week in Germany.
NHS workers would soon be tested at 'drive in centres' run by the likes of high street chain Boots, Mr Gove revealed.
Strikingly, he also took a swipe at Beijing over the early spread of the virus, saying: “Some of the reporting from China was not clear about the nature, the scale, the infectiousness of it.”
And he declined to say who would pay for the looming recession and black hole in the public finances, saying: “The most important thing at the moment is to save lives.”
Mr Gove faced questions about the length of the lockdown after Professor Neil Ferguson, a government adviser, warned it would have to continue until June.
Even then, schools and universities should not reopen until the autumn and people should be told to continue working from home rather than return to their offices, he argued.
Mr Gove said “The reason all of us are making these sacrifices is because all of us will have people whom we love who are at risk from this virus.
“I can’t make an accurate prediction, but everyone does have to prepare for a significant period when these measures are still in place.”
On the peak of virus cases and deaths – after the 1,000 mark was reached on Saturday – Mr Gove said: “It depends on the action all of us take.
“If we practice the social distancing measures, if we follow the rules the government has outlined, if we follow that good scientific advice, then we can delay the infection rate and that gives our NHS the chance to become more resilient.”
It prompted suggestions the UK could copy some EU countries in telling people not to leave home at all to exercise – or allowing them to do so only with slip of paper.
But Mr Gove declined to comment on what the prime minister was hinting at in his letter.
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies