Uber is protesting against plans by London mayor Boris Johnson to cap the number of minicabs operating in the capital.

Proposals to limit the transport are expected to be set out in newly elected Conservative government’s Queen’s Speech, which outlines the legislative programme for the year ahead and will take place on May 27.

However Jo Bertram, Uber’s regional general manager at UK, Ireland and the Nordics, has written a letter asking to debate the matter with the mayor, in what is only the latest regulatory strife facing the beleaguered taxi app firm.

"London is one of the great cities of the world and Londoners have embraced Uber’s technology; tens of thousands rely on us for their job and millions more use us to get where they need to go," she wrote, according to the Financial Times.

"Capping the industry’s ability to grow would mean higher prices and less availability for the millions of people who rely on Uber and services like ours to get around."

Johnson, who is in his last year of a two-term stint as London mayor, is under pressure to cut down on pollution in the capital, following an order from the Supreme Court in April that it be brought in line with EU limits.

Companies like Uber have also faced hostility from London’s black cab owners, who complain they are being undercut by the company’s drivers who do not have to adhere to the same regulations.

Speaking to the FT, a spokesman for Johnson said: "The mayor is not on an Uber witch hunt.?It doesn’t matter who the drivers work for. It just doesn’t make sense to have such a large number of minicab drivers in the capital.

"We must be able to take action against the threat posed by the massive increase we are seeing in the number of private hire vehicles."