Boris Johnson told the UK in a televised address that those who cannot work from home should attempt to return to work immediately, while following social distancing rules and avoiding public transport.

Many manufacturers have already been working during the lockdown while observing distancing protocols, as have essential retail outlets. Most of the UK's housebuilders said last week they were to resume work.

However, many business leaders say this edict lacks clarity or detail, a view supported by opposition leaders.

A full document containing details on the easing of lockdown is expected at 2pm today followed by a statement to the House of Commons by Mr Johnson at 3.30pm.

Among other concerns from business leaders is the level of Government support going forward. Currently one in four workers is on furlough and having 80 per cent of their wages paid from the public purse. However chancellor Rishi Sunak has intimated that this cannot continue in the long term.

British chamber of commerce director General Adam Marshall said: “Businesses share the Prime Minister's ambition to see more people return safely to work over the coming weeks.

“Companies will do everything they can to protect employees and customers, maintain social distancing and operate successfully as more sections of the economy are permitted to re-open.

“Businesses will need to see detailed plans for the phased easing of restrictions, coordinated with all nations across the UK and supported by clear guidance. It is imperative that companies have detailed advice on what will need to change in the workplace, including clarity on the use of PPE.

“Firms will also need to know that government support schemes, which have helped save millions of jobs in recent weeks, will continue for as long as they are needed so that they can plan ahead with confidence.

“The timing of further easing of restrictions must be guided by the public health evidence, but businesses need their practical questions answered so they can plan to restart, rebuild and renew.”

Responding to the Prime Minister’s COVID-19 update this evening, Federation of Small Businesses (FSB) National Chairman Mike Cherry said: “Tackling this virus and ending the threat to public health remain absolutely paramount. But it is also necessary for thought to be given to the future of work and business.

“It is clear from the Prime Minister’s provisional plan that the reopening of the economy is likely to be gradual, and the support for small businesses will need to reflect that.

“For small employers, there should be a way of partially furloughing staff, so that a small business which is only able to get up and running again steadily can bring back workers some of the time, but retain them via the Job Retention Scheme the rest of the time.

“We look forward to seeing more detail tomorrow on workplace guidance. We have contributed to the Government’s thinking and need to see the result of that if this is to come in any time soon.

“There must also be clarity for businesses in different parts of the UK on where guidance differs between Scotland, England, Wales and Northern Ireland.

“Maintaining appropriate social distancing, in line with official advice, is vital. Small businesses will need help with the costs of adapting to that, such as through a back-to-work voucher, to allow the limited, safe reopening of their businesses to be financially viable at a time when economic activity is low and cashflow tight.

“Small businesses will need time to adapt after the workplace guidance is published, and for smaller businesses it must be proportionate and focused on the overall outcome of maintaining safe working environments, achieved as straight-forwardly as possible.

“Smaller businesses will need support to help them to comply with the necessary requirements, and some may need financial help to adapt workplaces and purchase personal protective equipment.

“There also remain important practical questions around transport infrastructure and childcare, which are intrinsically linked to efforts to revive the economy while maintaining all necessary health steps to tackle COVID-19."

Helen Dickinson OBE, Chief Executive of the British Retail Consortium, said: We share the view of the Prime Minister that safety is what counts when determining when shops can reopen. Already retailers around the country are working on plans for reopening safely and with all necessary social distancing measures in place.

"The BRC and Usdaw have supported this process with our own social distancing guidance, learning from the experiences of thousands of supermarkets and other essential retailers. It is vital that the reopening of stores is based on who can do so safely, as opposed to trying to draw lines in terms of different sizes or types of shop.

“Further clarity is needed in coming days and we look forward to more details from the Government. We need a plan for shopping as well as shops – this means a plan that allows safe navigation both to and through our retail centres – and we look forward to continuing to work closely with the Government to support this process.”

And lanie Leech, Chief Executive, British Property Federation comments: "We urgently need the Government to publish the detail in its back-to-work papers and what public health guidance will apply as more people return to their places of work and have more freedom to enjoy public spaces.

"The overwhelming priority is to make sure that people are safe, but businesses will need time to prepare for and apply this guidance. As property owners and managers we have a critical role to play and we will work with our tenants in offices, warehouses and shops to support them and to make sure that the public spaces we are responsible for are safely managed.”

Yorkshire businesses call for urgent clarity on return to work rules