Organisers of this summer's World Police and Fire Games in Northern Ireland have insisted they will be ready on time.
They are under increasing pressure to find a venue for the opening ceremony after rugby bosses ruled out Ravenhill.
It had been hoped the event, which is less than six months away, could be staged at the east Belfast stadium, but the Irish Rugby Football Union refused the request, claiming it would clash with plans to unveil their revamped facility.
Alistair McGowan, head of marketing with the 2013 World Police and Fire Games, admitted they faced a huge challenge but was confident they would find a fit-for-purpose facility. He said: "We would like to have been further down the line in terms of the stadium. But the actual organisation of the Games is very, very well advanced."
Almost £15 million of Government funding is being spent on constructing new stands at Ravenhill. The building work will increase capacity to 18,000. The Department of Culture Arts and Leisure (DCAL) is also part-funding the Police and Fire Games - billed as the third largest international multi-sport event in the world - which will run for 10 days in August.
More than 25,000 visitors, including 10,000 competitors from 70 different countries, are expected in Northern Ireland for the event. An athletics village is being set up at Custom House Square in Belfast city centre.
Mr McGowan said his company was engaged in detailed discussions with other venues but declined to disclose their location. He told Radio Ulster: "It is not just about the stadium, it is also about the contents and Belfast City Council has done a great job in putting that together. They are 95% ready."
Alternatives include the former Maze prison site and the recently redeveloped Titanic Quarter, but the choice has been limited because refurbishment of Windsor Park and Casement Park are likely to be under way in August.
Michael McGimpsey, who sits on the DCAL scrutiny committee at Stormont, described the situation as deeply disturbing. The Ulster Unionist MLA said: "There is no excuse for this failure as we have been aware since as far back as 2007 that the Games would be hosted here. I am also surprised that this issue was not brought to the attention of the culture, arts and leisure committee sooner."
It is understood 35 venues across Northern Ireland have been secured for the 65 sports. Many of the track-and-field events are being held at the Mary Peters Track in south Belfast which has received a multimillion-pound upgrade. Belfast's Waterfront Hall, the Odyssey arena and Bangor aquatics complex are also being utilised. The Games are expected to generate up to £15 million for the local economy. Sports Minister Caral Ni Chuilin declined to comment.