Paris lost out to London in the bid to host the 2012 Games
The head of the Paris bid team for the 2012 Olympics believes London's budget problems stem from false promises made during the bidding process.
Last week Olympics minister Tessa Jowell caused alarm when she admitted the Government would not have bid if it had known a recession was coming.
This did not surprise ex-Paris 2012 boss Philippe Baudillon as he always felt London had talked down costs.
"Paris's bid was much, much more precise," said Baudillon.
"London underestimated a lot of costs and we can now see the real costs were much higher than they were in the bid.
Our vision for the Games is big - as it should be. This project is fully on track
"The people from London 2012 were much better salesmen than the people from Paris. But it is much more difficult when you have the contract and you've made a lot of promises that are not linked to reality."
London, largely thanks to a last-minute lobbying effort ahead of the final vote in Singapore, beat favourites Paris, Madrid, Moscow and New York for the right to stage the Games in 2005.
But since then London's organising committee and the Government have been dogged by arguments about the actual cost of the Games, particularly as the overall economic picture has worsened.
The London bid was very optimistic in terms of costs. I say optimistic but I could use another word
Former Paris 2012 boss
This week alone there have been further negative headlines about Olympic sponsors dropping out and London venues being scrapped.
Jowell's quickly clarified comments were seen as a statement of the obvious by some and an embarrassing gaffe by others.
For the 53-year-old Baudillon, who now runs the French division of US media giant Clear Channel, the seeds of London's current problems were apparent from the start of the bidding campaign.
He now sees London's problems as two-fold.
"First, the London bid was very optimistic in terms of costs. I say optimistic but I could use another word," said Baudillon.
"And second, there is (an economic) crisis, which is unpredictable. So you have a lot of problems with private finance and the budget.
"But it would have been easier for Paris to deal with the crisis because our bid was linked to (former International Olympic Committee vice-president) Dick Pound's recommendations in 2003 about the size of the Games, the legacy and the use of temporary venues. We worked hard on that.
"I am sure London will organise the Games perfectly because the British people are very good at that. But London's bid was not done on this basis, it was based on a huge operation to improve east London."
The French proposal was far less ambitious, according to Baudillon, and elements of it - enlarging the Roland Garros tennis complex and building a new aquatics centre - have been pursued despite the shock failure to win the vote in Singapore.
This is evidence, he feels, of how the Paris bid was in tune with the city's needs and would not have placed an unnecessary burden on the region's tax-payers.
"The IOC itself has to realise you cannot use the Games to make revolutionary changes in a city or country," he said.
"It is too expensive, too huge. The times have changed. Beijing is the last Games that can be done like that."
Baudillon's remarks will be dismissed by some as sour grapes but many observers will know they contain more than a hint of truth.
For its part, London's organising committee issued a statement that reiterated its commitment to delivering the project on time and within the revised budget. It also pointed out the most recent IOC inspection awarded London 9.75 out of 10 for its work so far.
"Our vision for the Games is big - as it should be," a London 2012 spokeswoman told BBC Sport.
"We have a world-class team in place across this large and complex project delivering our ambitions, not just for a truly memorable Games but a Games that leaves a lasting legacy for sport, and regenerates east London.
"This project is fully on track and we are getting on with the job."