This overhaul will mark a major break with the more cautious approach traditionally taken by the Treasury, which has led Philip Hammond, Chancellor of Theresa May, to be dubbed “Spreadsheet Phil”.
In a speech to influential think tank Onward on Tuesday, Mr Barclay, leading a review of all spending at Whitehall, will describe the Treasury as “the new radicals.”
The reshuffle is likely to lead to moves similar to the government’s controversial £ 400million investment in OneWeb, a bankrupt satellite company, as part of its plan to replace the use of the navigation system by EU satellite.
It is also likely that ministers will follow a series of collision courses with senior officials. Last week it emerged that Sam Beckett, the business department’s senior official, had requested a written “ministerial directive” formally ordering officials to acquire the stake in OneWeb, warning that the money could be lost.