The project's Hybrid Bill must still pass through both Houses of Parliament to confirm the planning approval. But with Committee stages over, and major sticking points - not least the addition of a station at Woolwich - now resolved, this is expected to be a formality.
Executive chairman of Crossrail's promoters Cross London Rail Links, Doug Oakervee, said Royal Assent for the Bill was expected in around six months. "This will enable detailed design and essential enabling works then to move forward, with full construction under way from 2010 and services commencing in 2017."
The project is expected to give the civil engineering sector a huge boost over the next decade, providing work for 14,000 people to build the line, and a host of companies across the supply chain.
Although four separate multi-disciplinary consultancy (MDC) design contracts were let earlier in the year, it is expected the firms, Arup, Atkins, Halcrow, Mott MacDonald and Scott Wilson along with development manager Bechtel, will look to form a single design team for the project.
All will meet this week to discuss the potential make-up of this delivery group, likely to be based on the model established by Rail Link Engineering - Arup, Halcrow, Bechtel and SNCF subsidiary Systra - to deliver High Speed One for London & Continental Railways.
However, it is also understood that management of Scott Wilson's design work package for the overground sections at each end of the line is likely to be novated to Network Rail, which will act as the client.
Crossrail's funding will come from three main sources: Government funds, Crossrail passenger fares, and a levy on London business rates.
This money is supplemented by additional cash from Canary Wharf and the City of London Corporation, and BAA for a station at Heathrow.
Chancellor of the Exchequer Alistair Darling confirmed the public funding on Tuesday as part of his Comprehensive Spending Review of public spending.
London Mayor Ken Livingstone praised the decision and said it would give a boost to some of the most deprived parts of the capital.
"With a capacity twice that of the Jubilee line, and expanding London's rail capacity by 10 per cent, it is the largest addition to London’s transport system for more than fifty years," he added.
But shadow transport minister Theresa Villiers criticised the Government for not approving the scheme sooner. "Of course we welcome the news that Crossrail has been given the green light, as we welcomed it in 2001 and 2005, but why has it taken Mr Brown 10 years to commit to the funding?" she said. "His dithering has cost billions for the taxpayer," she added claiming that each year waiting for final approval had cost £300M.
Crossrail will be the largest infrastructure project in Europe, linking Maidenhead and Heathrow in the east through 16km of twin 6m-diameter tunnels in central London, out to Shenfield in the east and Abbey Wood, via Woolwich in south-east London. 24 trains per hour will travel along the 118km of track.
London Rail 2007
Crossrail will be discussed in detail at NCE's London Rail conference on 6 November. Cross London Rail Links corporate affairs director Clinton Leeks will update delegates on the project's progress alongside other key London projects including Thameslink and the Docklands Light Railway upgrade.
What happens next
2007: Crossrail bill has been passed through the select committee process in the House of Commons and is proceeding through Parliament
2008: Royal Assent likely to be granted in the summer. Once the Crossrail bill receives Royal Assent and becomes an act of Parliament, construction can begin
2009: Enabling works begin
2010: Construction expected to be underway
2017: Crossrail services due to commence