This will include help with finance, HR and legal as well as the technical advice needed to bring the business to life.

The idea is similar to one being piloted by Skanska, which has put up a cash pot for in-house teams to fund upfront costs of green efficiency improvements for clients.

Outsourcing contractor Mitie launched the industry’s most ambitious scheme – Mitie Millions – last February. The firm has put together a £10m fund to encourage any entrepreneurs to start-up Mitie Model businesses.

Costain hopes the idea will spur its transformation from contracting into a full-service provider of front-end engineering consultancy and design, through construction to back-end care and maintenance.

Staff with ingenious ideas will get the opportunity to work full-time developing them and getting the business off the ground.

Ross Agnew, Costain’s Group Strategy Director, said: “Costain is committed to providing intelligent solutions to our customers’ problems and we also recognise how difficult it is to get good ideas off the ground.

“We believe that innovation is integral to our business model and this is just one way in which we are looking to support this.

“This is an exciting opportunity for anyone who has ever wanted to run their own business and who has an idea that provides new intelligent solutions to meet our customers’ needs,” said .

Agnew said the company will consider all ideas that align with Costain’s business strategy.

The scheme is open to everyone within the business, including its supply chain and customers.