Cardiff City's plans for a new soccer stadium have raised serious concerns with planners in a neighbouring council.
The Bluebirds' ground, Ninian Park, is an ageing stadium
Vale of Glamorgan Council is worried that a new 60,000-seater development on the edge of the city could cause further traffic congestion problems.
Cardiff City FC - promoted to the First Division in May - has long wanted to replace its dilapidated Ninian Park home ground.
Recent success for the Bluebirds has given fans hope that their side will be given the venue it deserves.
And Cardiff County Borough Council believes that a Premier League club with a stadium to match would attract visitors to the city and bring a boost to the local economy.
The club has unveiled plans for a £100m stadium opposite the existing ground.
To raise money for the project, Cardiff's council is proposing to sell the valuable surrounding land for a 400,000 sq ft retail development.
But Rob Thomas, head of planning for the neighbouring council, has said development of this kind in the area could cause huge problems.
There are plans for a £100m stadium development
"There will be a significant impact from traffic movements to and from these developments," he said.
"The accumulative impact is such that it is going to have a major effect on the Vale of Glamorgan highway network."
An independent report has indicated that having a Premier League club in the city could attract millions of pounds worth of investment and bring hundreds of new jobs.
Cardiff City says it needs the new stadium to make the Premiership.
Planners will decide next week on whether to give the project the go-ahead by granting outline planning permission, and will be considering letters received in support and against the idea.
The scheme is supported by Cardiff Council and has also been welcomed by Cardiff Chamber of Commerce, which sees the site as a good spot to carry out the type of retail activities not easily carried out in the city centre.
Among those who have voiced their objection to another Cardiff stadium is the Welsh Rugby Union, currently shouldering debts of £60m.
The WRU's chief executive David Moffett has urged Cardiff City not to press ahead with the development.
He wants the club to use the Millennium Stadium - which would have the double benefit of removing competition for events and maximising use of the existing facilities.
The 74,000-seater stadium has been trying to attract a wider range of major sporting events, including show-jumping and boxing tournaments.