The launch of London’s all-night tube service is to be delayed.

The service was originally due to launch on September 12, but the BBC reports this is no longer the case.

No reasons have been given for the delay, but members of four unions have been involved in recent strike action in a dispute over conditions offered to drivers working on the Night Tube service.

There’s no indication of when the service is now expected to launch, but during the recent strike on August 6, London mayor Boris Johnson said he was “not fussed” about the night service starting on 12 September, as long as it started at some point in the autumn.

The service, which is set to operate on Friday and Saturday night, will see five of the network’s tube lines run all night when finally open, and bring a welcome boom to London’s night-time economy.

The extended opening hours were announced in September 2013, and was welcomed by London’s clubbers, most of whom would do anything to avoid nightbus journeys in the city wherever possible.

You can find out which lines make up part of the Night Tube here.