Traffic was disrupted as the procession of 200 black cabs travelled from Regent's Park to the Department of Transport in Marsham Street.
Drivers are angry at plans to introduce licensing for 60,000 minicabs, bringing London into line with the rest of England and Wales.
There has been concern over attacks by drivers on passengers, accidents involving uninsured cars and former criminals at the wheel.
Ministers favour a two-tier system with minicabs being bound by less stringent regulations than hackney drivers who can ply for trade on the street.
Bob Oddy, secretary of the Licensed Taxi Drivers Association, which represents most of the 22,000 black cab drivers, said: 'It is a cowboy's charter.
'If the Government is serious about protecting the public they should insist that minicabs comply to the same standards as us - doing the Knowledge, having their vehicles checked equally rigorously and their fares controlled, as ours are.