The £9.325 billion Olympic project is in a "worryingly tight" financial position, Public Accounts Committee (PAC) chairman Edward Leigh said.
Olympic building work is on track for test events in 2011 but contingency funds could still be hit by unforeseen problems, he said.
The Olympic Delivery Authority (ODA), which is in charge of Olympic build and infrastructure, has £1,270 million left from the original £2,747 million contingency.
Much of this is earmarked to meet predicted risks, leaving only £194 million "headroom," the PAC found.
Speaking as the PAC, published its report on preparations for the London 2012 Games, Mr Leigh said: "What's worrying is that the financial position is tight.
"Of the sum left within the Olympic budget for contingencies, £1,270 million, most is currently earmarked for known risks.
"But unforeseen problems continue to emerge to place fresh demands on the contingency."
Another £160 million of contingency could be called upon to cover previously unplanned work to secure and maintain the Olympic Park between the end of construction to the handover to the Olympic Park Legacy Company (OPLC) shows the project continually faces cost pressures, the PAC warned.
But it is also possible that all of these risks may not happen, it was noted.