The “dynamic discounting” scheme went live in March and letters were sent to suppliers last month.

Tarmac denied the scheme would be used at its contracting business when first contacted by the Enquirer in April.

But is has now confirmed that suppliers from a cross section of the business – including contracting – have been “invited to participate” at this “very early stage” of the scheme.

Tarmac’s Early Payment Programme allows suppliers to bid for faster settlement of invoices on a live system run by financial technology specialist C2FO.

A letter explaining the scheme states: “On a daily basis Tarmac shares information with CF2O on available cash flow and indicates an average discount rate that suppliers can offer to access this money, in exchange for earlier payment of invoices.”

A Tarmac spokesperson said: “We’ve launched our Early Payment Programme to provide supply chain partners with a simple way to manage cash flow and access more flexible payment options, should they wish to use it.

“We believe that supporting our partners in this way is essential to maintaining and strengthening positive long term relationships.”