London bus workers went ahead with a strike on Friday in a dispute over an Olympic bonus, threatening travel chaos in the capital.
The walkout by thousands of members of Unite at 17 bus companies in pursuit of a £500 payment for working during the Games will hit most parts of London, disrupting travel for commuters and tourists.
The action went ahead even though three companies - Arriva, Metroline and London General - were granted a last ditch injunction in the High Court on Thursday by Mr Justice Supperstone preventing Unite members they employ from going on strike.
It is understood that the workers going on strike represent about 85% of the total workforce.
Hopes had been raised that the strike could be averted after London mayor Boris Johnson announced that £8.3 million was available for bus companies to pay a bonus, but talks at the conciliation service ended without agreement.
Mr Johnson said: "I am saddened, disappointed and enormously frustrated that despite brokering £8.3 million of funding, union leaders and the private bus companies have failed to reach agreement, and as a result it looks likely that Londoners will face unnecessary and needless disruption.
Bus workers across the majority of London's bus network will be on strike
"It seems to me that some militant union leaders remain hell-bent on strike action, and that is wholly unacceptable.
"I want the people of London, and our honest and hard-working bus drivers, to know that we've gone the extra mile, money is on the table, this offer is fair, but it is also conditional on drivers not taking strike action."
The union accused the employers and outside influences of "ambushing" the court over the "unprecedented" injunction, which Unite said was granted without any reasons given.
Unite said the strike will see workers in more than 70 of the capital's bus garages walk out.
The union blamed the disruption on the refusal by Transport for London (TfL) and the bus operators to negotiate a meaningful settlement.
Unite vowed to appeal against the court ruling.
Strikes will go ahead at London United, London Sovereign, Stagecoach East, Stagecoach Rainham, Stagecoach Selkent, Arriva North, Arriva South, First Capital, First Centre West, London Central, Abellio West, Abellio South, Metrobus, Docklands, Blue Triangle, CT Plus and Arriva Southern Counties.
Unite London regional secretary Peter Kavanagh said: "Bus workers across the vast majority of London's bus network will be on strike. This comes despite an injunction which was given without any proper explanation.
"It begs the question of whether the court has come under any external pressure in making the ruling.
"Granting an injunction in the face of a massive vote for strike action is an affront to democracy. We are fast becoming a country where justice rules in favour of big business and tramples on the rights of ordinary working men and women.
"We will appeal this anti-democratic decision. It will only serve to deepen the resolve of London bus workers.
"The failure by the bus companies to negotiate seriously and their desire to run to the courts will only heighten tensions. The decision by these three bus companies runs contrary to the mayor's call to pay London bus workers an Olympic bonus."
Peter Hendy, London's transport commissioner, said: "It is, and always has been, for the bus companies and Unite to resolve this dispute Given their inability to do so, the mayor obtained - unprecedentedly - £8.3 million from the Olympic Delivery Authority (ODA).
"This would allow every bus driver in London in a garage where one or more routes were affected by the 2012 Games to gain, over the 29 days of the competitions, about £500.
"As I understand it, the bus companies made three offers to supplement this with more of their own money, but the Unite leadership have refused to budge from their position of £500 after tax for everybody, and indeed have asked for more during the course of the negotiations.
"The union leadership have also refused to defer the strike to give time for further negotiations or for any of the offers to be put to their members.
"The mayor has made it clear that the money he obtained from the ODA is only available if there is no strike. Our message to London's bus drivers is: you should work normally and, if you do, the extra money brokered by the mayor is still available.
"The only conclusion to be drawn from this is that the Unite leadership were never serious in wanting to settle for additional money for their bus drivers, and their strike is going ahead without their members having been asked whether or not they will accept any of the employers' offers.
"Following the outcome of a legal challenge by three of the bus-operating companies, an injunction has been granted which prevents the strike going ahead in significant areas of north west and south London."