A HYBRID bill for London's eastwest Crossrail project will go before the next session of parliament, transport secretary Alistair Darling announced this week.
Darling said that the review of Crossrail's business case carried out by Network Rail deputy chairman Adrian Montague, and made public this week, made a clear case for the project.
But he said that at £10bn the project was still a huge challenge to deliver and fund.
An increase in business rates in London is expected to raise £2bn, with the Treasury left to pick up the rest.
This price, said Darling, was too high. He said he had told project promoter Cross London Rail Links (CLRL) to make the scheme cheaper.
Montague's report said that axing the proposed branch to Richmond and Kingston and replacing it with a branch to Maidenhead via Heathrow Airport would bring capital costs down from £8.9bn to £8.6bn.
Whole life costs would also fall from £13.5bn to £11.9bn while maintaining a benefit to cost ratio of 1.97:1.
The Richmond branch had been strongly backed by the Strategic Rail Authority (SRA) as it would relieve congestion at Heathrow.
But last week's Rail Review wound up the SRA and handed the project over to be run by the Department for Transport and London mayor Ken Livingstone's Transport for London department.
Darling said the case for a limb to Richmond was relatively weakly developed and that an extension on the western side to Maidenhead might be a better solution.
'This would be a key change, and would align directly with key review concerns about the scale and deliverability of the project and the number of interfaces it has with the national railway, ' he said.
The Montague review raised concerns that CLRL's proposed peak service level of 24 trains per hour in the central section might not be achievable due to crossovers with Network Rail trains.
It also questioned whether there would be sufficient capacity in the construction industry for the scheme to be delivered on time and without significant escalation in labour costs.
It added that a number of other potential projects tied to London's Olympic bid and the regeneration of the Thames Gateway would increase pressure on market capacity.
Promoters of the rival London Regional Metro (LRM) bid, drawn up by Arup/AECOM, seized on the review's findings as vindication for their own scheme, despite the Montague report's dismissal of the LRM plan as failing to offer substantially new thinking .
An incremental approach is fundamental to LRM, which also includes a branch out to Reading via Heathrow.