Boris Johnson is under growing pressure to stop non-essential construction workers heading to building sites as the country attempts to tackle the spread of Covid-19.
He has faced calls from across the political spectrum for more stringent rules so workers are not placed at risk, and public transport is not overwhelmed.
Mr Johnson, who will appear before MPs today for Prime Minister's Questions in the Commons, has so far resisted the pressure.
The coronavirus death toll in the UK reached 422 yesterday - up from 335 the day before and the largest day-on-day increase in the number of deaths since the outbreak began.
In measures announced on Monday, the PM told people to only go to work if ‘absolutely necessary’.
But on Tuesday, Health Secretary Mr Hancock said those who cannot work from home, including key workers in the NHS and social care, should go to work ‘to keep the country running’.
He said construction workers were among those who could continue to work as long as they could remain two metres apart at all times.
But some builders and construction workers have said they feel ‘angry and unprotected’ going to work, while others are under pressure from employers to go in.
Conservative former cabinet minister Sir Iain Duncan Smith added his voice to the calls, telling BBC Two's Newsnight: “I think the balance is where we should delete some of those construction workers from going to work and focus only on the emergency requirements.”
Andy Burnham, mayor of Greater Manchester, told the programme: “This decision about allowing non-essential work appears to be taken for economic reasons when actually - when you're in the middle of a global pandemic - health reasons alone really should be guiding all decision making.”
London Mayor Sadiq Khan's office said the Government must act urgently to get more people staying at home following construction workers reporting to building sites and images of packed Tube trains appearing on social media.