Lecturers are threatening industrial action to support their demand for more money to meet the costs of living in London.
Natfhe, the lecturers' union, cites research showing that workers in the capital need an extra pound;4,200 a year to compensate compared with rates of up to pound;2,502 which are paid in inner London.
Staff in 25 further education colleges in London are being balloted for a one-day strike on May 13.
A Natfhe spokesperson said: "The call for a pound;4,000 allowance is reasonable considering the police get pound;6,165, schoolteachers pound;5,943 and fire-fighters pound;4,300."
It was thought that London weighting would be taken more seriously after Natfhe joined the Association of Colleges and jointly lobbied Parliament two years ago.
Ivor Jones, the AoC's director of employment policy, said: "AoC has asked Natfhe to make a claim through the established channels. The next opportunity is on May 7."
The AoC and unions including Natfhe are organising a further lobby of Parliament on May 19.