The construction giants are among a host of firms promising to back the Prime Minister’s Supply Chain Finance initiative.

With Supply Chain Finance a bank is notified by a large company that an invoice has been approved for payment.

The bank is then able to offer a 100% immediate advance to the supplier at lower interest rates, knowing the invoice will ultimately be paid by the large company.

Cameron said: “I praise the commitment made by the businesses today and the wider support they provide to their supply chains.

“This Government is determined to back all those businesses who aspire to get ahead and take on more people.

“In the current climate, viable businesses can struggle to get the finance they need to grow – this scheme will not only help them secure finance and support cash flow, but will help secure supply chains for some of our biggest companies and protect thousands of jobs.

“It can be a win-win, with large companies and small suppliers both benefiting from this innovative scheme.

Cameron also said that the Government will look to offer this to its own suppliers.

John Walker, National Chairman, Federation of Small Businesses said: “The new Supply Chain Finance scheme could help smaller firms in two key areas – improving their working capital and tackling the issue of late payments.

“Nearly three quarters of small businesses report that they have been paid late in the past year, placing a huge strain on cash-flow and meaning they struggle to realise ambitions to grow.”