After a value-for-money investigation by the Government's Advisory Committee on Advertising, the DoT is expected to return to the COI fold and spend its £12 million-a-year budget through COI.
However, COI will admit that valuable lessons have been learnt from the DoT's experiment and will change its procedures to take account of the experience.
The outcome of the ACA's review was being announced this Thursday by Alan Bishop, COI's chief executive, and Charles Skinner, the director of communications at DoT. A small committee will be set up to analyse further DoT claims that it saved money by going it alone rather than via COI.
The ACA review is believed to have cast some doubts over the DoT's figures and the committee's work is expected to result in the department coming back under the COI umbrella.
The outcome is seen by the Government as a sensible compromise and not a victory for either COI or the DoT. Since Bishop took over at COI in January, he has sought to rebuild bridges with Skinner, who clashed with Carol Fisher, Bishop's predecessor.
The ACA, which monitors government ads, wants departments to use COI in order to maximise Whitehall buying power. It was surprised when the DoT appointed six COI agencies to its new creative roster. The cabinet office minister responsible for COI, Douglas Alexander, made clear in an interview in Campaign last month that he would like to see transport campaigns run through COI.