Caborn is confident that London's planning in on track

American Jack Lemley resigned earlier this month as Olympics Delivery Authority chairman.

He said: "I went there to build things, not sit and talk about it, so I felt it best to leave the post and come home."

Caborn responded: "I am disappointed by Jack. The IOC came over here and gave us a clean bill of health."

Speaking at the Financial Times Sports Industry Summit in London, Caborn continued: "The board he was on was one of the strongest we put together. It is made up of top industrialists.

"They are not politicians, they are top executives. I have every confidence in the board. There is no political interference."

By any analysis we have made a strong start and hit all our major milestones DCMS statement

Lemley, who has never previously left a construction contract early, feared the project could be delayed by local politics.

"I felt it was better to come home now than face that in five or six years," he explained.

He was surprised by the opposition of some of the 300 local businesses to moving away from the site in Stratford.

"Some of the people were happy to move, and some of them weren't. In any event, there was a huge amount of local politics.

"Those are the kind of things that confuse and frustrate the process."

And Lemley was also unhappy about plans to convert the Olympic Stadium into a football stadium.

"A football field is not compatible with an athletic stadium," said the 71-year-old.

However, a spokesman for the Department of Culture, Media and Sport (DCMS) refuted Lemley's claims and said it is important to start planning the legacy of London 2012 now.

"It is a strength of the project that we have been having a debate about long-term legacy use of 2012 facilities now - rather than years in the future.

"This project has been defined by strong political co-operation from the outset and that remains the case.