Network Rail has been forced to redesign its £650m revamp of London Bridge station to prevent congestion from future tenants of the neighbouring Shard

The rail operator said predicted footfall had “shifted significantly” since work started on the Shard and is now working on plans to enable a greater flow of people through the station.

Network Rail said: “The design job is different to when we started because Transport for London has predicted higher passenger levels.”

The move has delayed the awarding of the contract. It was due to be advertised in late 2009, but will not now appear in the Official Journal before the autumn.

It is the largest tender in the £5bn Thameslink upgrade and will include a new station and track layout.