The majority of members have backed a motion calling on the mayor Sadiq Khan to ditch the requirements for written tests for Uber and other minicab drivers due to the disproportionate and unfair costs, and replace it with a £25 verbal test.
“It is of course vital that taxi drivers can communicate with their passengers in English," said Labour assembly member for Lambeth and Southwark Florence Eshalomi.
"However the estimated £300 to take the test seems a disproportionate cost, especially when you bear in mind drivers will soon be required to pass an advance driving test at costing £149. In addition, every time a driver isn’t on the road they are losing pay."
She added: "There are other tests which could be used that cost just £25. It’s time for the mayor to look into other options – what we don’t want to see is people losing their livelihoods."
The assembly members are also pressuring the mayor to snatch greater powers from Westminster over regulating private hire vehicles.
They backed a motion calling on Khan to lobby for powers to make the right to benefits such as holiday and sick pay a condition of getting a license to drive an Uber or other minicab in the capital.
It follows a separate ruling by an employment tribunal last year which said the Uber drivers who brought the case should be considered workers, not self-employed.
That decision, which Uber will also appeal, has been followed by a similar one regarding a plumber working for Pimlico Plumbers, while a further tribunal involving Deliveroo drivers is due to be heard in May.
"Tackling low pay is one of the mayor’s top priorities and there are still too many Londoners who don’t have the security they deserve at work," said a spokesperson for the mayor.
"The mayor though still has limited powers around the licensing of the private hire industry – including not being able to cap the numbers of private hire providers, nor consider issues like drivers’ access to rights at work like sick pay and holiday pay.
"The mayor continues to lobby the government for more powers over London’s private hire industry, so he can continue to drive up standards and ensure a high quality of service for all passengers."
Lobbying for additional powers was part of Khan's major plans to shake up the taxi and private hire industries in the capital, announced last year. Among the greater powers devolved to London in the chancellor's Spring Budget on Wednesday, these were not among them.
The rise of the so-called gig economy has spurred a string of reviews by the government into this new way of working and the high profile rows over workers rights. The work and pensions committee heard recently from Uber drivers who painted two very different pictures of their experience with the company.