The Home Office is working on a package to tackle the Metropolitan Police's recruitment crisis.
Officials say one possibility would be London weighting.
Starting salaries of £16,000 and low morale have contributed to the Met's recruitment problems. It currently has 26,267 officers, compared with 28,400 in 1993.
Dave Rodgers, vice-chairman of the Police Federation in London, said, "The police in London are unique and we should not be compared with other forces.
"We have a recruitment crisis, no two ways about it. We are actually losing more people than we are recruiting.
"We are just not attracting and keeping people because they cannot afford to live in London.
"There is no housing allowance and because there is no overtime there is no possibility of supplementing their income."
Rodgers welcomed the possible introduction of London weighting, but he said that alone would not solve the problem.
The move follows a call by the Met's former commissioner Sir Paul Condon for London weighting or "pay lead".
A Home Office spokesman said, "We are looking at a package of measures to help overcome problems with recruitment, in particular, one option is a London pay lead."
A Met spokeswoman said, "The housing allowance went in the mid-90s, as well as overtime for inspectors and above.
"We have a recruitment crisis. We are trying to retain them but we are competing in a very buoyant marketplace."