The renovation of West Ham United’s London Stadium could end up costing £1bn, according to a senior Conservative politician.

Taxpayers have had to foot much of the bill, which currently stands at more than £753m, for developing the former Olympic Stadium.

The spiralling costs have prompted Mayor, Sadiq Khan, to order an enquiry into the conversion, and London Assembly member Andrew Boff expects the eye watering sums spent on the Hammers’ new home to rise further still.

“The money is mounting up. I wouldn’t be surprised if we get rid of a billion on this thing,” he told BBC London’s Inside Out show.

“As far as I can see there is no end to the taxpayers’ money being used to prop up this white elephant – they’ve been effectively given this stadium and the taxpayer is paying for it.”

West Ham contributed just £15m towards the conversion costs of £321m and will pay £2.5m a year as part of its lease.

The initial price for making the ground football friendly, which involved the instillation of retractable seats, was originally expected to be £154m.

This figure rose to £193m due to issues with the roof, before a report by a coalition of 14 supporters’ trusts revealed another increase to £753m in November.