Building trains for the Crossrail ‘super tube’ now under construction is being delayed for a year to save costs, it has been revealed.

Contract time is being shortened and put back closer to the line being completed will save tens-of-millions of pounds, the company has claimed.

Trains will be introduced on the Great Eastern Main Line in East London from May 2017 as each one comes off the production line, rather than the entire fleet being delivered earlier and “put in storage.”

It means contract awards won’t be put out to tender until next year.

This will allow the Government to make sure British manufacturers are on an equal footing with foreign companies under EU purchasing rules.

Some 60 trains will eventually be needed when the line opens in 2017, connecting existing East and West London rail lines via a seven -mile section under central London.