London's 23,000 bus drivers want a standard wage and a cut in driving hours to correct "huge disparities" between operators, a union has said.
The union wants bus drivers' wages raised to at least £30,000 a year
Unite said bus drivers' salaries can vary from £20,000 to £28,000. It wants the minimum wage raised to £30,000.
Unite has also demanded standard conditions on working hours and driving time, "in the interests of public safety and our drivers' health".
Transport for London said bus companies and unions would discuss the issue.
Drivers perform the same duties and drive the same buses, yet their pay and conditions vary significantly between the six large firms and numerous small firms which operate buses in London, the union said.
Unite's senior regional industrial organiser Peter Kavanagh said: "Bus workers keep this city moving.
"Our members carry six million passengers in the capital every day, more than all other modes of transport put together.
"They work in extremely stressful conditions, and many of them, especially those working for companies at the lower end of the market, cannot afford to live in our city."
The union wants drivers to be allowed at least 20 minutes to carry out bus safety checks before beginning to drive.
It has also called for drivers to spend no more than four-and-a-half hours driving continuously before being allowed a break.
A spokesperson for Transport for London (TfL) said: "We are sure the trade union and the bus companies, who agree pay and conditions, will discuss them as part of their normal negotiations.
"Bus drivers provide a valuable service to Londoners, and their pay and conditions should reflect that."
Extra police patrolling
Meanwhile, TfL has said that police teams will patrol central London buses, following the success of similar teams in outer London.
Last year an extra 440 police and community support officers were deployed in outer London boroughs.
TfL said this contributed to an 11% fall in bus-related crime across London, between April and September of last year.
New teams will now start operating in boroughs including Westminster, Camden, Hackney and Islington.
Mayor Ken Livingstone said: "These teams will be highly visible on the busy buses of central London where they will provide a reassuring presence for Londoners and visitors to our city."