Brentford and Swansea have issued a joint statement calling for more fans to be allowed in to the Sky Bet Championship play-off final on Saturday at Wembley.
Both clubs have questioned the 10,000-capacity limit set for the match, compared to the 21,000 who were present as Leicester beat Chelsea in the FA Cup final earlier this month.
Brentford chief executive Jon Varney called the decision 'incredulous and unjustifiable', and admitted that the football authorities were 'powerless' to increase the crowd limit without Government intervention.
Varney said: 'We feel it is unjust that only a few days ago, more than 20,000 fans were admitted to the FA Cup final and advanced discussions were taking place for Wembley to host the Champions League final with a similar number of fans attending.