LONDON, Aug. 16 (Xinhua) -- The London mayor, Sadiq Khan, said Thursday that he is seeking powers to limit the number of Uber drivers in the British capital after a similar move in New York City.

The mayor warned British Transport Secretary Chris Grayling a "huge increase" in mini cabs in the city is causing increased congestion, pollution and leaving many drivers struggling to earn a living.

He said the number of private hire drivers in London has almost doubled from 60,000 in 2011 to present 110,000.

Officials in New York last week approved a cap on the number of licences for ride-hailing cars, which will impact app-based services such as Uber and Lyft.

Of the 96,326 black for-hire vehicles in New York, 77,571, 81 percent, are affiliated with Uber, according to figures obtained by the New York Post from the city's Taxi and Limousine Commission.

Khan described a similar move in London as a "necessary step."

In his letter to Grayling, he wrote: "Unlike New York, I don't have the power to cap the number of private hire vehicles in London."

"I am writing to again urge the government to grant me that power as the mayor of London -- alongside appropriate restrictions on cross-border hiring, to enable Londoners, like New Yorkers, to breathe better air and live in a less congested city."

Around 45,000 drivers work for Uber in London, according to the company. The mayor said that drivers' livelihoods had also been affected.

Uber recently won a 15-month licence to continue operating in London after its attempt to renew a five-year licence was refused b the Transport for London last September.

An Uber spokesman said, "Uber is committed to helping address congestion and air pollution and we strongly support the mayor's ultra low emission zone."

"Already more than half of the miles travelled with Uber are in hybrid or electric vehicles," the spokesman added.