Amey and Balfour Beatty became the first contractors to agree last week to advertise subcontractor work opportunities on the Government’s official free contractor finder website.

The Government initially hailed the move as a major step forward in its drive to push more public spending into the hands of smaller firms.

The deal means contractors can bypass their established supply chain arrangements for the open tendering approach now favoured by Cabinet Minister Francis Maude for subcontractor packages.

But the Cabinet Office then insisted to the Enquirer that the new arrangements would not replace existing supply chains.

A spokeswoman said: “This is not about bypassing established supply chains, it is about making the process more transparent and giving SMEs a chance to get more work.”

Balfour is using a Scottish Government website to tender fit-out packages on its £10m job at a crime lab in Gartcosh in Lanarkshire.

Amey insisted that it would continue to use its existing supply chain.

Maude said that Balfour and Amey are among nine major companies across all industries “opening up their supply chains to greater competition by advertising their sub-contracting opportunities on Contracts Finder.”

He said: “It’s very simple – if you allow more businesses and more business models to compete- you find better value solutions.”

The Contracts Finder website gives businesses a single place to survey everything on offer from Government and currently has 97,000 viewings per week.

One major contractor told the Enquirer: “It seems like mixed messages are coming out on this one.

“First we are told it’s all about supply chains then this hits us and it seems like it’s open tendering time again.

“The current system seems to work pretty well and this looks like Government meddling in something specific to make a wider political point about helping smaller firms.”

One subcontractor said: “The whole situation is totally confusing.

“Is it worth us going for a supply chain place when the rules can be changed at any time and the whole process thrown open to anyone?”