Work on several of the venues is running behind schedule
More must be done to make sure the cost of the 2014 Commonwealth Games in Glasgow does not rise again, according to an official report.
The public spending watchdog Audit Scotland said that preparations for the games were progressing but warned that major challenges lay ahead.
The report comes days after the budget for the Games was increased by £81m.
It also said several of the venues were unlikely to be ready by the dates suggested in the original bid.
Earlier this week it emerged that the cost of hosting the Games had risen from £373m to £454m.
Audit Scotland's report was compiled before that budget increase was announced.
Caroline Gardner, deputy auditor general, said: "In the current economic climate public sector finances are already under pressure and it is essential that the organisers keep costs under control.
"They need to continue to monitor and review the budget assumptions regularly."
The report also highlighted how several of the venues will now be ready later than predicted in the bid document.
The National Indoor Sports Arena was due to be complete by next March next year but will now not be ready until the end of 2011.
The Cathkin Braes cycling course is now expected to be complete in March 2012, almost three years late, and the refurbishment of Glasgow Green hockey complex and the national swimming centre have also slipped behind schedule.
However, Audit Scotland stressed that all the venues and transport projects would still be delivered in time for the Games beginning in July 2014.
John Baillie, chair of the Accounts Commission, said: "Although a key feature of the bid was that 70% of the infrastructure, including venues, was already in place, delivering a high quality Commonwealth Games to a fixed deadline presents major challenges for the four main organisers.
"It is crucial that risks are well managed as plans progress towards hosting the Games in 2014."
A 38.5 hectare athletes' village will be built in Dalmarnock for the Games
Glasgow Conservative MSP Bill Aitken called for a parliamentary statement on the issue.
He said: "Unless a firm hand is exercised, this project could spiral out of all control.
"Taxpayers need to know which budget will bear the costs and what else will be cut to pay for the increased costs."
Labour agreed that a "firm hand" was needed "to prevent any overrun" and the Liberal Democrats said the Games budget was likely to "creep up" with the Scottish government's budget being "raided to plug the gaps".
A Scottish government spokeswoman said: "The Audit Scotland study is a snapshot of Games planning activity up to August 2009.
"The Government and our Games partners have made substantial progress in recent months and this has a bearing on many of the findings.
She added: "Most significantly, the Games partners recognised the risk posed by an insufficient budget to the successful delivery of the Games and our ability to secure a lasting legacy.
"That is why the organising committee announced a budget increase of £81m. Audit Scotland have recommended, this will help to manage one of the major risks facing the Games."