The capital's "cabbies" are furious that they are banned from driving in some of the special lanes reserved for Olympics traffic and fear they will lose money because London will be so congested during the Games.
Hundreds of taxi drivers brought the streets around parliament and Big Ben to a standstill this week, hooting their horns and moving at a snail's pace. They are threatening to hold more protests before the Games begin next Friday.
"I'm a bit sick of the Olympics now. The sooner it's over, the better", said taxi driver Shane Ludlow, 42, at a cab rank in the heart of the City of London financial district. "It's pretty disgusting that we can't use the Olympic lanes. It's our city."
Hailed from the kerbside by briefcase-bearing commuters and tourists alike, black cabs have been a traditional London sight for more than a century and their horse-drawn predecessors date back to the 17th century. Their trade is worth nearly £1 billion a year, according to one union estimate.
As recognisable as red double-decker buses, their image has even adorned Olympics publicity materials and official memorabilia and many drivers might have hoped for a bonanza as thousands of visitors flood the city for the Games.
"We were used as icons, as an iconic vehicle to promote London as an Olympic venue," said Steve Mepham, a committee member of the United Cabbies Union.
"Why should we be unable to go around and earn our living in a normal way? We're not asking for 500 or 600 pound bonuses."
Many of London's 25,000 taxi drivers want access to all sections of a temporary network of lanes reserved for Olympic athletes, officials and the media. Black taxis are currently only allowed in two thirds of the 100 mile network.
Nicknamed "Zil lanes" after the limousines used by senior officials in the old Soviet Union, they are designed to bypass the huge traffic jams expected in London's narrow streets.
But cab drivers, who study the road network for years in a test called "The Knowledge" before the authorities give them a licence, say the decision to exclude them will leave them stuck in traffic and unable to stop to pick up or drop off passengers.
"It's absolute rubbish," said cab driver James Mahoney, 67, from Essex, east of London. "We're getting nothing from the government. We're the safest cabs in the world but the Mayor and the Olympic committee are not giving us anything, not letting us dip our beak in and just earn a living."
Unlike London's bus and train drivers, cabbies will not receive any bonus payments for working during the Olympics. In February, the city's transport authority, Transport for London, rejected a request from the drivers' union to raise fares by 22 per cent.
The decision fuelled resentment among taxi drivers - never shy of giving passengers their opinions on perceived injustices - that their welfare and livelihoods were being ignored.
Cab drivers said road closures and altered traffic signals had already disrupted their daily work and a downturn in traditional off-the-street business had cut take-home pay.
"There's no street work, there's no one coming over doing business. Most of the places it's quiet," said one cab driver with 29 years' experience, waiting for work a short ride from the Tower of London.
"This week, I'm taking the same money I was taking 25 years ago. I'm getting 50 percent of what I usually do," added the driver, who asked not to be named.
As the countdown to the opening ceremony entered its final week, Transport for London continued to encourage Londoners to walk, cycle or work from home to beat the crowds.
The London Olympics Organising Committee played down the impact the Games would have on cab drivers.
"We believe the games are a great opportunity for all sorts of people including taxi drivers. We are sure people visiting would love to use their services," said a LOCOG spokesman.
But Steve McNamara, a spokesman for the Licensed Taxi Drivers Association, which represents over 10,000 of the British capital's black cabs, rejected LOCOG's statement.
"The whole situation is ill thought-out and just a disaster," he said. "We think the Games are good for London and LOCOG tell us there is a price to pay for them, but it shouldn't be any price."
John Mason, director of London Taxi and Private Hire, which licenses black cabs for TfL, said: "We have worked hard to provide drivers with information about operating during Game-time and as much access to the Games Lanes as we can.
"Along with all other motorists, black cabs can use the Olympic Route Network and TfL has agreed additional concessions, including the use of turns along the Olympic Route Network that were initially banned for all traffic except buses."
Despite those concessions, some cab drivers are still angry with London Mayor Boris Johnson.
"Boris, give us a little bit, let us earn our living. That's all we want," said cab driver James Mahoney.