A number of businesses in Dublin city centre are set to challenge the College Green Bus Gate scheme in the High Court today.
Under the scheme, private cars are banned from College Green during the morning and evening rush hours in order to free up the area for buses.
Earlier this month, Dublin City Council said the initiative had led to a 6% increase in pedestrians and a 62% increase in cyclists in the area.
However, the 13 firms behind today's action claim their business is down by 30% as a result of the scheme.
The companies include Brown Thomas, Louis Copeland and Q Park.