The government’s procurement agency is working up plans to publish the contents of contracts with public bodies

It follows a recent pledge by David Cameron that a future Tory government would force the publication of all contracts worth more than £25,000 with any public body.

The move could see the details of PFI and PPP deals laid bare and allow the public to scrutinise what services are bought for the public sector’s £42bn annual expenditure on construction.

Building understands Nigel Smith, chief executive of the Office of Government Commerce, has asked the agency to work up plans to implement the Tory proposals under the protocol that allows civil servants to prepare for a change of government.

A source close to the OGC said: “The OGC will spend the next two months working up plans, trying to understand how the system might work, and whether it might be possible to start with a pilot.”

However, Ian Pearson, economic secretary, questioned how deliverable the plan would be. He said: “I believe in public transparency, but also in commercial confidentiality. My concern is that if we publish everything there will be such a huge amount of redacted information it’ll be like MPs’ expenses, and will take a huge amount of work and expense.”

Graham Watts, chief executive of the Construction Industry Council, said: “We have to be sure there aren’t unintended consequences to this.”

The news came as the OGC’s Smith launched his own drive for greater internal transparency of contracts across government departments. He said: “I believe there are no real legal obstructions to this. Why don’t we know what suppliers are charging other departments?”