A London Tube strike will go ahead after talks between the two sides at the conciliation service Acas ended without agreement.
RMT union members on the Piccadilly Line, which serves Heathrow Airport, will launch a 48-hour walkout from 12:00 BST on Wednesday 26th September, and a five-hour strike from 20:30 on Friday 28th.
Transport for London (TFL) warned there would be little or no service, including on the Night Tube on Friday.