Chelsea have significantly increased the projected cost of redeveloping Stamford Bridge to more than £1 billion, which would make it the most expensive stadium in Europe.

The club have yet to reveal a price for the ambitious project but The Times has learnt that internal discussions have placed the cost at double the £500 million that was estimated when they received planning permission for the 60,000-capacity stadium from Hammersmith and Fulham council in January.

Chelsea’s plans, drawn up by the Swiss architects Herzog & de Meuron, are among the most ambitious and complex stadium-design projects attempted. The cost of building Tottenham Hotspur’s new ground, which is due to open at the start of next season, has almost doubled to £800 million and Chelsea’s stunning rebuild