Taxi drivers brought parts of London, Paris and other European cities to a standstill yesterday as they protested against new private cab apps such as Uber which have shaken up the industry.
Thousands of London's black cabs, many of them beeping their horns, filled the roads around Buckingham Palace, Trafalgar Square and the Houses of Parliament to the exclusion of any other vehicles.
In Paris, hundreds of drivers blockaded the French capital's airports and staged a "go-slow" during the morning rush hour, while protests were also staged in Madrid, Barcelona, Berlin, Rome and Milan.
Long-running complaints about competition from private hire and unlicensed taxis have been crystallised by the new challenge posed by smartphone-dependent car services.
California-based company Uber is the main target of the drivers' ire, thanks to an increasingly popular app that is now used in 128 cities in 37 different countries.
Uber allows customers to order and pay for a car using their phone, with geo-locating technology connecting them to the nearest taxi driver.
Unlike other private hire cabs - those that must be pre-booked - Uber drivers use the app to fix the fare, rather than it being calculated by a central operator.
Critics say this amounts to a meter such as those used by traditional London taxis, and say that Uber cars should therefore be subject to the same tough regulation.
"We're governed by a set of rules and they don't seem to apply to Uber," said Glenn Chapman, a 46-year-old driver parked in a long line of cabs outside Downing Street.
But the irony of the protest is that it has provided widespread publicity for the app, and Uber has taken advantage by offering discounts during the strike.
The London protest was joined by drivers across Europe, where the focus on Uber has reignited long-running disputes about the introduction of private hire cab services.
On Tuesday, the Spanish region of Catalonia also warned it would fine any unauthorised Uber drivers up to €6,000 (HK$63,000).
Drivers in France have staged several protests recently, and hundreds of vehicles blockaded the main Roissy and Orly airports in Paris yesterday, many displaying the banner "taxis on strike" and "No to unfair competition".
In Rome, taxi drivers were planning a "reverse strike" by charging only €10 per trip to fall in line with competitors' prices. In Milan and Madrid, taxis staged a day-long strike, while hundreds of drivers parked up for a protest in Berlin.