Taxi drivers in several cities have been taking part in unofficial action to highlight what they say is an oversupply of licences.
More drivers than usual turned out for work today, although traffic disruption was kept to a minimum.
President of the National Taxi Drivers Union Tommy Gorman has called on the taxi regulator to put a moratorium on the issuing of new licences until a long-term solution is found.
The form of today's action was meant to highlight the problem as taxi drivers see it; too many taxis on the streets - and not enough customers.
In a statement this morning, the Commission for Taxi Regulation said that drivers were now operating in a liberalised market, and that it could not put a cap on the number of licences issued.
But Mr Gorman accused the regulator, Kathleen Doyle, of being dismissive of their concerns.
He said today was the start of an action plan to get their message through to her.
