Crossrail said it would unveil the winners this summer when it first advertised the jobs last August.

But a spokesman for the firm said this first date was only indicative and confirmed the jobs would now be awarded in 2011 in time for work to start in late 2011.

Contract C300 for the Western and C305 for Eastern Running Tunnels account for around 18km of the 21km twin bore tunnels beneath London.

The delay leaves the 14 contractors bidding the jobs on tenterhooks at a time when order books are starting to shrink.

Package C300 – Tunnels West comprises the construction of twin 6.2m diameter bored tunnels from Royal Oak and a Portal (west of Paddington Station) through to the new Crossrail Farringdon Station, length of drive approximately 6.2km.

Package C305 – Tunnels East comprises the construction of twin 6.2m diameter bored tunnels from:

• a launch chamber at Limmo Peninsular through to the new Crossrail Farringdon station, length of drive approximately 8.3km;
• a launch chamber at Stepney Green through to Pudding Mill Lane Portal, length of drive approximately 2.7km; and
• a launch chamber at Limmo Peninsular through to Victoria Dock Portal, length of drive approximately 0.9km