The debate has become so heated that Rhodri Morgan, Labour's shadow spokesman on Welsh affairs, says the issue goes to the heart of the nation. "What we are witnessing is a struggle over the soul of Wales," he said.
The Millennium Commission is expected to make a decision on funding for the two projects by the end of the year. While it is saying publicly that each application will be dealt with individually and that funding both projects has not been ruled out, the Welsh Rugby Union says it has been advised that the two projects can not both go ahead.
Plans for a stadium were put forward by the WRU and South Glamorgan County Council, which advocated a pounds 110m multi-purpose sports and leisure complex with a retractable roof on the site of the National Stadium at Cardiff Arms Park; pounds 55m is being sought from the commission.
All was going smoothly until recently. Then, instead of approving noises that had inspired confidence, the feedback was far from positive. The WRU says it has been forced to bring the argument into the public domain because it was being undermined. "Strings are being pulled in the corridors of power by a small group which wants an opera house," said a spokesman.
Edward Jones, secretary of the WRU, said: "If it comes down to a battle between the two then I hope it comes over loud and clear what the public wants. If it is art versus sport, then sport should win in this case."
The Cardiff Bay Opera House has been a controversial project since being proposed in 1986. The choice of a design by architect Zaha Hadid provoked disagreement and though her appointment was confirmed, there were changes to the design. The pounds 86m project seeks pounds 50m from the commission.
Lord Crickhowell - the former Welsh Secretary Nicholas Edwards, who is chair of the Opera House Trust - entered the debate when he told a meeting of the Cardiff Business Club: "It is regrettable some connected with the WRU are putting it around that it is necessary to campaign against the opera house."
Mori is to undertake a poll to gauge the support for the stadium, which would be used to stage the 1999 Rugby World Cup.
However, Lord Crickhowell said: "The story of our millennium bids, opera house and rugby ground illustrates our ability for disagreement and argument, so that we may miss the chance which is available."Reuse content