Seven Sisters Overground station, which lies on the Weaver line, was due to have lifts installed this year to provide passengers with step-free access.
But Transport for London (TfL) has confirmed that the project is currently paused while “a funding shortfall” is addressed.
This means new lifts are unlikely to be in working order by the end of the year.
The delay has been blamed on issues with the certification of a new type of lift by Network Rail and the manufacturer, as well as “general inflationary pressures”.
A TfL spokesperson said: “This project is being funded and delivered as part of the Department for Transport’s Access for All scheme and we hope to get clearer direction on how and when this will be delivered very soon.
“We remain supportive of the plans to provide step-free access to the London Overground platforms at Seven Sisters.”
The Department for Transport (DfT) has said that ministers are “carefully considering funding” for the Access for All scheme, and will provide more details in due course.
It is understood that the proposed design and estimated costs for the Seven Sisters upgrade project are still being reviewed by Network Rail.
Other Overground stations currently earmarked for step-free access in the coming years include Brondesbury, Hackney Downs, Peckham Rye and Surrey Quays.
