Mr Khan announced his investigation into the conversion cost – up from £272m to £323.
Sky News claims the cost of the retractable seats, installed to improve the view for football, has risen from an estimated £300,000 to £8m.Engineers have said work to move them could take 15 days at the end of the football season and 15 days to put them back after the summer – three times as long as the five days initially predicted for each period.
Mr Khan is said to be deeply concerned at the cost increase, with deputy mayor Jules Pipe telling Sky News they have inherited “a mess” from predecessor Boris Johnson.
“Last year the previous administration told the public that the costs had risen in total to around £270m. The new Mayor has now been told that cost will be over £320m.
“Understandably, Sadiq has ordered an investigation as to why those two figures are so wildly different.
“As the new administration at City Hall clearing up the mess of the previous administration, we need to make sure that the stadium runs on a sustainable basis and it is affordable to London.”