Prime Minister Boris Johnson is facing growing calls to intervene and stop non-essential construction workers heading to building sites as the UK looks to slow the spread of coronavirus.
MPs from across the political spectrum have called for more stringent rules so workers are not put at risk of getting COVID-19 and public transport is not overwhelmed.
Cabinet Office minister Michael Gove told Sky News on Monday that construction on open air sites can continue but workers should follow "social distancing advice".
However, many builders have pointed out this is almost impossible on construction sites where hundreds of them work together, often having to be in close contact and eating in packed canteens.
Mr Johnson is expected to confront the issue at Prime Minister's Questions later today in the House of Commons.
Some builders said they feel "angry and unprotected" going to work, while other say employers are pressurising them to come in so they are concerned they will not be paid if they stay at home.
A Cabinet Office spokesman told Sky News those who cannot work from home should go to work if they are feeling well.
He added that the government is expecting employers to ensure employees are social distancing and are able to do so - but added the situation will remain under review.
On Monday evening, the government announced a recruitment drive for 250,000 volunteers who are in good health and can help vulnerable people.
Health Secretary Matt Hancock also announced that an east London exhibition centre would made into a new NHS hospital with 4,000 beds to cope with outbreak.
The efforts to deal with the pandemic came as the UK saw its biggest daily spike in deaths from coronavirus with 89, taking the nationwide total to 424.
The number of confirmed COVID-19 cases in the UK now stands at 8,077, up 1,427 from 6,650 on Monday.
The prime minister said people could only go to work if "absolutely necessary" on Monday when he announced new measures.
But on Tuesday, 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 keep working - as long as they could remain two metres apart at all times.
Sir Iain Duncan Smith and Andy Burnham are among the politicians calling for changes to be made.
London mayor Sadiq Khan's office called for the government to act in order to get more people to stay at home as photos appeared on social media showing busy Tube trains.
Elsewhere, the health secretary said 11,788 recently retired NHS workers had responded to calls to return to work, including 2,660 doctors, more than 2,500 pharmacists and 6,147 nurses.
Mr Hancock said: "I pay tribute to each and every one of those who is returning to the NHS at its hour of need."
He also said about 5,500 final-year medics and 18,700 final-year student nurses were set to "move to the front line" next week.