Under the agreed plans, an overall delivery partner will be appointed to project manage the scheme in a similar role to that provided by the consortium of CH2M, Laing O’Rourke and Mace (CLM) for the 2012 Olympics.
And in a change to the original plans, design contracts for the tunnelling, stations and railway systems are expected to be packaged up into frameworks for greater flexibility.
Under the original plans, the design packages were split into three geographical areas including the central tunnel between Paddington and Liverpool Street; the western section to Maidenhead and eastern section to Shenfield.
But these packages are expected to be brought together into a central framework. "This will give us access to a wider pool of resource and give us more flexibility in how the works are packaged," said a source close to the project.
"We want a framework where people can come together in a more integrated way. For example if one of the firms is struggling for resource there is a risk of the work not getting done on time so we need the flexibility to draw on other resources."
The Crossrail team will also "learn lessons" from the Olympic Delivery Authority and CLM. "We will clearly be looking to learn lessons such projects," said the source.
"We've already seen that it takes time to fully work out the rules and responsibilities of the Delivery Partner to ensure there is no duplication of responsibilities with the client. We will be working to ensure there is greater clarity."
Should the procurement process be formally agreed this week, contract notices for detailed design will be published soon on the European Union Official Journal.
In a written answer to the shadow transport minister Theresa Villiers, Tom Harris this week revealed that legal consultants had been paid £8.6M, financial consultants £1.3M, and £2.8M had been paid to 'other' consultants, including engineering consultants, since 2003/4.