The rise came as 2012 chiefs highlighted cost-cutting measures on the project in response to the Comprehensive Spending Review.

Olympic Delivery Authority chief executive David Higgins said the Games’ budget had been reduced by £20m thanks to a series of efficiency savings.

But the effects of economies have been counter-balanced by a rise of £11m on the Aquatics Centre to speed-up construction work and an extra £10m in “performance management” bonuses for CLM for reaching “agreed milestones and savings achieved.”

The ODA’s latest financial report stated: “CLM’s enhanced payments are based on performance and they are incentivised to drive down costs across the programme.”

The extra £10m will see CLM’s fees to deliver the Olympics rise to £694m according to the latest final cost estimates for programme delivery. The other members of the consortium are Mace and CH2M Hill,

One industry source told the Enquirer: “You’ve got to hand it to O’Rourke, they know how to negotiate a contract.”