Drivers marched to City Hall, home of the Greater London Authority on Tuesday, to ask for greater parity with Tube drivers.

The march follows moves by Mayor of London, Ken Livingstone, to end the Tube drivers' long-running dispute over pay last week.

But Mr Livingstone says he has no power over bus drivers' pay.

The erosion of pay since the privatisation of the late 1980s means bus drivers' pay has fallen by �120 a week compared with average earnings

March organiser Peter Kavanagh

The Transport and General Workers Union (T&G) says London's bus drivers have lost out on millions of pounds of pay and pensions since the privatisation of the buses.

They currently earn an average salary of �17,000, 45% less than Tube drivers who are paid an average of �31,000.

The union says it wants to highlight the chronic shortage of drivers in the capital.

It says there are 1,000 bus driver vacancies at a time when the Mayor is calling for more people to use public transport and putting greater pressure on the bus industry.

March organiser, Peter Kavanagh said: "The erosion of pay since the privatisation of the late 1980s means bus drivers' pay has fallen by �120 a week compared to average earnings.

Privatised

"The situation in London is worse with bus drivers now earning �230 a week less than the London average."

He added there should be equal investment in the bus services as well as parity in pay and conditions.

Mayor Ken Livingstone told BBC London he had sympathy with the drivers but was powerless to do anything.

"The real problem is that they've all been privatised so they're dealing individually with private companies.

"I can't intervene - it's not like I'm going to be taking over the buses next year as I am the Underground."