Firms will be allowed around 10 operatives and two supervisors to work laying out social distancing procedures on site.

It now looks like phase two, the so-called soft start, to allow a small part of the workforce back on site is unlikely to be backed by the Scottish Government before mid June.

This will only be allowed where strict social distancing can be maintained.

Only later in phase three will around 30% of the site workforce be allowed to resume work.

Yesterday the Scottish First Minister’s office set out further details for the ending of lockdown.

“From tomorrow, the construction sector is expected to be able to implement the first phase in its restart plan.

“A move to ‘phase 2’ of the construction sector’s plan will follow consultation with government to ensure it is safe to do so in line with public health advice.”

At the fastest, this consultation is expected to take at least two weeks.

Construction Scotland, the industry leadership group, also published the updated construction re-start plan and latest guidance yesterday.

This instructs contractors to “consult with the health and safety representative selected by a recognised trade union or, if there isn’t one, a representative chosen by workers.

It adds: “As an employer, you cannot decide who the representative will be.”

Minister for local government, planning and housing, Kevin Stewart, said: “This guidance also emphasises the importance of ongoing risk assessment with full input from trade union or workforce representatives and to keep all risk mitigation measures under regular review so that workplaces continue to feel, and be, safe.

“In parallel to the preparation of this guidance, Construction Scotland has published Site Operating Guidance and a Restart Model for the industry and I am very grateful to them for the significant work that has gone into producing those documents.

“The measured approach laid out in this guidance and the construction sector’s own restart plan provide a clear pathway to a phased restart of construction work in coming weeks and months.”