London Mayor Sadiq Khan says he told Prime Minister Boris Johnson “forcibly” that construction workers should not be going into work.
Mr Khan says he advised Mr Johnson at a Cobra meeting on Monday that quite a lot of construction was not “critical or essential”.
Mr Johnson placed the UK on lockdown on Monday evening.
But Housing, Communities and Local Government Secretary Robert Jenrick said later that work on building sites can continue thought workers should practise social distancing.
Advice for the housing, construction & building maintenance industries:🔹If you can work from home, do so.🔹If you are working on site, you can continue to do so. But follow Public Health England guidance on social distancing.🔹Outside of work, remember to #StayHomeSaveLives
— Robert Jenrick (@RobertJenrick) March 23, 2020
After more scenes of packed Tube trains on Tuesday morning, Mr Khan was asked if construction workers in London should be among the travellers
He told GMB: “My view is no and I made that point quite forcibly at yesterday’s Cobra, I made that point quite clearly to the Prime Minister.
“According to the Government’s advice the answer is yes’.”
His comments came as builders and construction workers said they felt “angry and unprotected” as they turned up to work on building sites following the introduction of the stricter coronavirus measures.
While some companies said they were closing sites down and suspending work, others said they would remain open with “strict precautions” in place.
Transport for London (TfL) announced on Tuesday that work on its and Crossrail sites was being temporarily suspended but that essential maintenance of the transport network will continue.
Housebuilder Taylor Wimpey also said that it has closed its construction sites, show homes and sale sites.
But earlier on Tuesday, rival Redrow said its sites remain open with “strict precautions in place including enhanced levels of cleaning, additional hygiene facilities and social distancing”.
Construction workers told the PA news agency that, although they are scared of catching the virus and taking it home to their families, they are reporting for work because otherwise they will not get paid and risk losing their jobs.
A crane operator at a London construction site with 400 to 500 workers said: “Everyone on site at the minute feels angry and unprotected.”
He said staff have been given no guidance on what was happening other than “just carry on until told otherwise”.
The man, who asked not to be named, said if he opted not to go in he “wouldn’t get paid or even could lose my job”.
“(It’s) scary really – I’ve got a family and kids at home. I’m in London around all these people, bringing it all back into an isolated home.”
Electrician Dan Dobson said the Government must provide support to self-employed workers – including about a million in the construction industry – and then shut down building sites.
He added: “It’s not going to change until support is offered to workers who are registered as self-employed.
“They have no incentive to stay at home, they have bills to pay.
“Everyone on site at the minute feels angry and unprotected.
“None of them want to go to work, everyone is worried about taking it (coronavirus) home to their families.
“But they still have bills to pay, they still have rent to pay, they still have to buy food.
“Construction sites will stay open until the Government issues an order to close.
“But the Government cannot issue the order to close until it offers support to the one million-plus construction workers – it has to go hand in hand.”