The government is looking for suppliers for the very early stages of its much talked about G-cloud framework for cloud computing.
A new notice on the Government Procurement Service calls for suppliers on four lots, each worth £60 million.
In a sign the government is looking to carefully experiment with the new delivery method, it is seeking suppliers for an initial six month term only.
The lots are infrastructure as a service (IaaS), platform as a service (PaaS), software as a service (SaaS) and specialist cloud services.
The government said in the notice that it was "putting in place a Pan Government Collaborative Framework Agreement for use by UK public sector bodies", including Whitehall departments, local councils and the NHS.
Companies interested in bidding have until 30 November to express an interest.
Although the initial values are low, if G-Cloud becomes a longer term project it is expected to draw in many contractors looking for lucrative deals.
Andrew Greenway, cloud lead for Accenture, said: "Some of the key challenges that the UK government faces in driving cloud adoption could be overcome by appointing a cloud broker, also known as an integrator, to work with the government to establish a catalogue of approved cloud services from the leading cloud service suppliers."
Such an approach could help meet security requirements, drive down costs and establish simple approval processes, he said.
It is not clear yet which contractors will bid, but all of the largest system integrators are likely to be interested. The real test, however, is likely to be whether the government sticks to its promise of also involving smaller firms and aiding their bid participation.