Morgan Sindall, Willmott Dixon and Bouygues are believed to be on board with Byles who is targeting schemes worth £1bn.

The trio are understood to be signing investment deals with Cornerstone which will put them first in the queue for contracts.

Byles left the school delivery body in June to set up Cornerstone which finds new uses for surplus public buildings.

The organisation has Carillion chief executive John McDonough as chairman and is planning a development pipeline worth £1bn over the next three years.

It is currently working with 12 local authorities and six health trusts targeting schemes in the education, residential and healthcare sectors.