Under a controversial new policy, every Edinburgh pub needs to have one toilet for roughly every 30 customers.
But licensing chiefs assume that half of all pub customers are women – meaning an equal number of male and female toilets are needed.
Dozens of firms across the city have been ordered to build new female toilets or face having their capacity drastically reduced.
Caledonian Heritable – the Edinburgh-based pub group – has taken its case against the policy to the courts.
A judicial review was launched last week into the case of the company's Pear Tree pub, on West Nicolson Street, which has three female toilets and saw its capacity reduced from 412 to only 200.
Separate reviews are to be launched later this week for Clark's Bar, on Dundas Street, and The Ormelie Bar in Joppa.
John Loudon, convener of the licensing law sub-committee of the Law Society of Scotland, has previously called for the licensing board to drop its policy.
Mr Loudon, who is representing Caledonian Heritable, said: "I hope that the licensing board will find that they do not have the power to do what they have been doing over the past two years.
"Our argument is they have no power to do this. Edinburgh is the only board arguing this."
At last week's initial hearing, the Pear Tree was granted an interim suspension of the decision to reduce the capacity while the case continues.
Leading industry figures hope that the case could result in the licensing board dropping its policy of cutting capacity for pubs that don't carry out the work.
One source said: "This is a really important case because it would be an important legal precedent in terms of what powers the licensing board has.
"The traditional-style relatively small pubs have been worst affected. Either you have to make major changes to your pub, which is very expensive, or you have to accept the reduction in capacity, so you're caught between a rock and a hard place."
The changes have come about as a result of building control officers enforcing on older premises the same standards they use for new properties.
The licensing board in Glasgow had been intending to enforce new capacity limits based on toilet provision but performed a U-turn last October.
A spokeswoman for the city council said: "The city's licensing board is committed to ensuring that premises meet appropriate public expectations for the present day."