GPs won a temporary reprieve after Brent PCT in north-west London gave them 12 working days' notice that the cut, worth £150,000 a year, would be imposed last month.
Cambridgeshire PCT has withdrawn support for face-to-face interpreters but backtracked on a similar threat to telephone and signing services.
But Brent PCT is planning to enforce the spending cut in April, leaving GPs unable to provide care for non-English-speaking patients.
A spokesman for Brent PCT said: 'This is a discretionary service and it is the GPs' responsibility to fund it.'
Brent LMC member Dr Gillian Braunold said that in her practice, where one consultation in 10 is interpreted, costs totalled £21,000 in nine months.
Seventy-four practices in Brent will lose funding but it will be retained in the five PCT-run practices. Thirty-five practices in the PCT area regularly use face-to-face interpretation.
Brent PCT took expert advice on the GP contract that 'supports our view that it's up to the GPs to provide the service,' the PCT spokesman said.