London would be brought to a standstill by a procession of black cabs protesting against the mobile app Uber. The drivers had, however, been warned by the Met Police that they faced arrest if they went ahead without the proper planning, The Telegraph newspaper reported.
Uber uses a mobile app to book rides in both licensed taxis and minicabs, and then measures the journey distance and calculates a fare which is paid direct to the driver.
According to the Licensed Taxi Drivers Association, Uber works like a taxi meter, which private cars are barred from using.
The association had helped to organise a protest which held out the prospect of ''severe chaos, congestion and confusion across the metropolis''.
Around 10,000 drivers are expected to converge on Trafalgar Square at 2 pm on Wednesday. According to rival app Kabbee, the disruption would cost the economy £125 million.
In an open letter to all, the Met Police has called on all licensed taxi drivers saying that the force was keen to ''facilitate a peaceful protest'' and to ''avoid serious disruption''.
The letter pointed out that it had not been approached about organising an official protest and urged the leaders of the event to get in touch to make arrangements.
The action would see roads around Trafalgar Square brought to a standstill from 2 pm. The action would see participation of around 12,000 drivers in the Europe-wide protest against Transport for London's (TfL) confirmation last month of its 2012 decision to grant web firm Uber a private hire licence, London Evening Standard reported.
TfL had insisted Uber's application was not tantamount to a taximeter - which only black cabs were legally entitled to use in London. The matter had however, been referred to the High Court, but a ruling was not due for several months.
Uber, backed by Google and Goldman Sachs, has 3,000 registered drivers in London.
According to Steve McNamara, of the Licensed Taxi Drivers' Association, the association wanted to create the maximum publicity for the minimum disruption and had deliberately avoided two days next week when the Queen would be hosting garden parties, London Evening Standard reported. He added they had nothing against competition but they felt that Transport for London had failed Londoners by allowing Uber to operate outside the law.
The report quoted Jo Bertram, Uber general manager for UK and Ireland, as saying the company fully understood that the action would cause a huge economic impact to London and Uber would send a message to its drivers in advance to encourage them onto the road. He added the company was very confident of the outcome of the High Court case.
(Also see: Uber Technologies at top of hot internet startup club with $17-bn valuation).