Taxi drivers have brought several European cities to a standstill by mounting one of the biggest ever protests against Uber, a US car service which allows people to order rides and fix fares with a smartphone application.
On Wednesday, drivers of hundreds of London's black taxis snarled traffic in the streets around Trafalgar Square, hooting their horns as they passed Downing Street, the home of Prime Minister David Cameron, and the Houses of Parliament.
In Paris, hundreds of drivers blocked 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.
"This about an all out assault on our profession, our livelihoods," said Max Small, a driver of one of London's black taxis for 34 years. "These big companies are coming in, not playing by the rules."
Taxi drivers across Europe level a variety of charges against Uber: that its applications break local taxi rules; that its drivers fail to comply with local insurance rules; and that it is therefore in breach of licensing and safety regulations.
Uber, backed by investors such as Goldman Sachs and Google, refute all those allegations, a spokeswoman said. Uber said its applications and its drivers comply with local regulations.
"What you are seeing today is an industry that has not faced competition for decades. Now finally we are seeing competition from companies such as Uber which is bringing choice to customers," said Pierre-Dimitri Gore-Coty, Uber Regional General Manager for Europe.
Uber has expanded rapidly since it was founded by two US technology entrepreneurs, Travis Kalanick and Garrett Camp, and now operates in 128 cities across 37 countries.
Ironically, the protest against Uber has provided the app widespread publicity, and the company has taken advantage by offering discounts during the strike.