The launch of the new all-night underground service linking Heathrow to central London has been delayed following a Summer of industrial unrest.

The new service would have launched on September 12 and would have operated throughout Friday and Saturday night, with trains out of Terminal 5 and the central area every ten minutes.

Transport for London has failed to reach agreement with the four unions involved so the proposal has been put on ice with no new date set.

“It’s terribly disappointing and would have been hugely beneficial to people catching late or early flights at the weekend” said one Heathrow worker.

Unions representing the train drivers say it would be too disruptive to their members’ “work-life balance”. They have already walked-out in protest at the proposal and threatened more disruption across the network.