Labour has called on the government to publish the full details of West Ham's deal to move into the Olympic Stadium "as a matter of urgency".
In a debate about the Olympic legacy, shadow culture secretary Chris Bryant highlighted the cost of the conversion and called it a "fiasco".
The cost of transforming the venue into a stadium ready for football has reached £272m.
Conservative MP and London Mayor Boris Johnson pointed the finger at Labour.
Of the £272m total transformation costs, £15m is being provided by West Ham United football club, who are occupying it from next season, with £1m coming from UK Athletics.
Mr Bryant told MPs the total spend on the venue would reach £700m, more per spectator than Wembley stadium, and more over budget than the total cost of converting the 2002 Commonwealth Games venue for use by Manchester City.
"This has the feel of a fiasco cooked up somewhere between the Mayor's Office, DCMS (Departure for Culture, Media and Sport) and the Treasury," he said.
"Which is why, in the interests of transparency, I urge the government to publish the full details of West Ham's secret deal as a matter of urgency."
Mr Johnson said "it was indeed" a mess that had been "cooked up", but said the former Labour mayor and then Labour government had been responsible.
"It was the Treasury under Alistair Darling and Gordon Brown who decided to go ahead with a stadium that was completely unsuitable for the purpose," he added.
Culture Secretary John Whittingdale said there were "good reasons" why full details of the arrangement with West Ham could not be published, saying things such as the terms of the rent should be confidential, as to publicise them could jeopardise future negotiations with possible tenants.
The parties also clashed over the sporting legacy left by the 2012 games, with Labour claiming participation had dropped in the following years in many parts of the country.
Mr Bryant accused the government of "an own goal, a dropped baton, a belly flop".
Mr Whittingdale criticised his "synthetic outrage" and said the London games had left an "amazing legacy".
"We were always clear that legacy was at the heart of our preparation" he said, saying strong progress had been made in terms of the regeneration of east London and increased sporting participation.