A shopping centre owner has applied for a judicial review into plans to build a leisure facility which would fund a new football stadium.
Luton Town FC wants to build a 23,000-capacity ground in the town centre.
But it says it needs to build Newlands Park, a shopping and leisure facility, at junction 10 of the M1 to finance the new stadium.
Capital and Regional, which owns the Mall shopping centre in Luton, claims the Newlands development is "unlawful".
The football club said the Mall owners application "does not come as a surprise" but it believed "their claims have no merit whatsoever".
Luton Borough Council, which approved the plans, said it was "disappointed" the shopping centre owner had challenged the decision.
In a statement, the council said it was "concerned about the potential cost to Luton taxpayers and the inevitable delays in this beneficial development coming forward".
"It is right that we vigorously defend the decision and we intend to do so," the council said.
Capital and Regional has been contacted for comment.
Newlands Park would include offices, a hotel, retail and leisure facilities in addition to a park and ride scheme.
As part of the town centre Power Court development, where the stadium will be built, there would also be a live venue, homes and "leisure and retail amenities".
Capital and Regional previously said it was concerned the developments could harm Luton town centre and other nearby areas.
The Mall owner had told the council it would apply for a judicial review as it believed "the grant of planning permission was unlawful".
In a statement Luton Borough Council said: "We remain entirely confident the decision-making process contained no legal flaws, which is a view supported by our legal representatives who have been scrutinising the grounds for challenge put forward."
A spokesman for Luton Town said the decision by Capital and Regional will "lead to delays to the regeneration of Luton".
"This action also goes against the interests of the community, of which 10,000 supported our applications in writing," he said.
Luton Town fans have previously said Capital and Regional had "declared war" on the community by opposing plans that hold the key to their new stadium.