One black cab firm is launching the legal action against Edinburgh City Council after it granted a licence for a rival private hire firm to open a new pre-booking office at the terminal of the city's airport.
Central Taxis, the capital's largest black cab firm, is appealing against the principle of a licence being granted for the company booking office yards from the private hire rank.
It is claiming in the action at Edinburgh Sheriff Court that the system is no longer in the spirit of the pre-booking requirement for private hire cars because passengers now go to the office and then walk out to the rank where their taxi will be waiting.
Central Taxis previously had a contract for five years, along with another private hire firm, to provide black cab and private cars for travellers at the terminal, which sees 25,000 passengers a day and is 30 minutes from the city centre.
City Cabs and Edinburgh City Private Hire won the latest contract to provide black cabs and cars at ranks at the airport terminal last year, but the private hire firm has only now had the permanent base approved.
An airport spokesman said it introduced wider changes to the layout to make it easier for travellers to move about the terminal and that its provision was legally sound.
One source claimed the distance between the new and old pre-booking offices is negligible, while opponents say it is enough to challenge the rules of pre-booking.
Tony Kenmuir, of Central Taxis, said he believed the booking method, which requires people to give a name and destination in an office before it is relayed to the car, is not pre-booking but "instantaneous".
He said: "We feel we have a valid argument and we are positive about the outcome of the appeal."
Kevin Woodburn, of Edinburgh City Private Hire, said he believed the court action by Central Taxis was motivated by "sour grapes" over losing the contract.
City Cabs declined to comment.
The council said it was aware of the Edinburgh Sheriff Court action.
Susan Mooney, the council's head of community safety services, said in her report to the licensing sub-commmittee that travellers had the clear option of both a taxi rank or hire car booking office at the terminal.
She said: "The booking will be logged on a computer and communicated to the driver of a vehicle in the pick-up area."
A spokesman for Edinburgh Airport said: "The initial contract had expired. We retendered, informed by our Surface Access Strategy, which allowed us for the first time to put our passengers' requirements at the heart of the decisions we make around taxi provision.
"We are observing and will comply with all legal and licensing requirements. Our primary concern is that the excellent service quality for passengers this offers is maintained. We are supportive of the diligent approach the council has taken.
"We are confident our taxi provisions are legal and, importantly, easy to use for our passengers. The council and its relevant committees agree with us.
"The current situation at the airport is very similar to the previous set-up, which was not challenged legally. It is also similar to many other major transport hubs across the UK."