Bank clerks, charity workers, university academics, council and National Health Service administrators get more money than teachers to work in London.
Evidence presented by the teacher unions to the review body shows that the current inner-London rate for school staff is Pounds 2,004.
Only two inner-city banks now pay a London allowance of less than Pounds 3,400, and more than four-fifths of building societies pay more. Both the BBC and ITV pay London allowances above those received by teachers - Pounds 2,369 and Pounds 2,588 respectively - as do charities such as the National Trust (Pounds 3,530) and Help the Aged (Pounds 3,423).
In the public sector, university academics receive Pounds 2,134, while administrators for local authorities get Pounds 2,211 and for the NHS Pounds 2,059.
The unions have urged the review body to raise substantially the inner-London allowance for teachers.
They also want it combined with the former inner-London supplement to form a single mandatory allowance to be matched by commensurate increases in both the outer-London and fringe-area rates.