The £10bn Crossrail project could increase the cost and slow the construction programme of the 2012 Olympics by obstructing the transportation of materials to sites.

The warning comes from rail freight operators and materials firms, who will present evidence to a House of Commons select committee that will be reporting on Crossrail in the new year.

Crossrail could affect the construction of the Olympics because it will use of depots in east London to store materials and machinery. These include sites in Bow, which are near the Olympic site in Stratford.

Graham Smith, planning director at freight operator English Welsh & Scottish Railway, said: “These are sites we would have expected to take stone to for the Olympic stadium. Without them, it will raise the cost of the Olympics and slow construction down, as lorries will have to carry the material there. The government has got a big, unresolved challenge to dovetail the Crossrail and Olympic programmes.”

James Day, managing director of materials firm Day Group, added that goods yards purchased by Crossrail in other parts of London could also harm the construction of the Games. These depots may be needed to process raw materials before they are moved to site.

A Crossrail spokesperson said it was working with the London Development Agency to create a building programme that complemented the Olympics.

Meanwhile, construction consultant Capita Symonds is drawing up a report that suggests that Crossrail could create a longer-term problem for construction projects in London.

The government has got a challenge to dovetail Crossrail and the Games

Graham Smith, EWS

The report, commissioned by EWS, has found that the number of rail freight trains using pre-existing Crossrail lines could be halved when the scheme opens, diverting 8000 tonnes of material an hour onto the roads.

EWS’ Smith said Crossrail’s timetable could halve the number of freight trains running into London to two an hour. Although most of Crossrail is an underground link, on the overground sections to Maidenhead, Abbey Wood and Shenfield, it will take over existing lines.

Crossrail wants 24 passenger trains an hour. This increases the current number on these lines, which means that some freight trains will be displaced. Materials firms Lafarge and Tarmac use the line to Maidenhead.

Smith warned that this would increase lorry use, which in turn would raise materials costs.