Designers behind plans for a new railway hub in central Birmingham have urged the Government to scrap the planned #550 million redevelopment of New Street Station.
Ove Arup, which is promoting a rival Grand Central station scheme at Eastside, described the New Street Gateway project as a largely cosmetic exercise that would not end the bottleneck of trains queuing to get into Birmingham.
The Solihull-based firm, one of the country's leading design engineering companies, claimed a capacity review carried out last year by Network Rail for the Department for Transport was fatally flawed and underestimated the likely growth in train usage.
Ove Arup's director of global rail projects, Colin Stewart, said the bottleneck approach to New Street from the east, where 12 tracks funnel into four, meant the new station would be running at over capacity by 2025.
It would have a "shelf life" of only 12 years if it opened as planned in 2013, he claimed.
Assurances by Network Rail that growth in passenger numbers could be accommodated by longer trains were rejected by Mr Stewart, who said few stations in the West Midlands would be able cope with the length of trains being proposed without costly platform extensions.
The claims were dismissed by Network Rail, which said it had every confidence in the capacity review.
"I would be very surprised indeed if a construction design firm had better predictions of growth than the Department for Transport," a Network Rail spokesman said.
The spokesman added that the Gateway scheme would be able to handle a 120 per cent growth in suburban and regional rail services by 2040 and would also solve the "passenger handling issue" by providing more space for customers to wait in comfort.
Grand Central station would be built at Eastside, on land reserved for the new city park.
It would link with Moor Street Station, allowing passengers to use a central ticket hall and change trains easily.
When first proposed in 1996, Grand Central had a price tag of #400 million. Ove Arup accepted the cost would be considerably more by now and would be largely dependent on raising private funding.
Mr Stewart urged the DfT to reject the business case for New Street Gateway because it "would not be a good use of public money", while Grand Central would provide a "very significant" increase in train path capacity.
"The Department for Transport has refused to carry out a review of this proposal, stating that it is not on their agenda, but equally has not criticised the idea," he said.
The chances of Grand Central being built appear slim. Birmingham City Council recently appointed a contractor to build the #13 million park and is committed to delivering New Street Gateway, as is Advantage West Midlands, the regional development agency, and Network Rail. The partners behind the Gateway scheme say the refurbished New Street will be able to cope with 150 per cent more passengers