London Underground will stage a test run of its new night service this weekend ahead of its launch next week.
During the night, trains will run without passengers on Friday and Saturday as staff make last minute checks before the service goes live.
It will start on the Central and Victoria lines before it is introduced for the Piccadilly, Jubilee and Northern lines in the autumn.
There will be six trains per hour on most lines between 00:30am and 5:30am.
The Northern line will have eight per hours to meet demand between Leicester Square and Camden Town.
The service was originally due to be introduced in September 2015 but was delayed by a string of tube strikes last summer by the RMT, TSSA, Aslef and Unite over the pay and conditions of workers.
A Transport for London spokeswoman said: “A service will be running on the Central and Victoria lines on Friday and Saturday nights. It won’t be open to any customers, it is purely for operational staff”.
In May, London Mayor Sadiq Khan called the service “absolutely vital” to his plan to “support and grow London’s night time economy”.
He said: "The Night Tube is absolutely vital to my plans to support and grow London's night time economy - creating more jobs and opportunities for all Londoners. The constant delays under the previous Mayor let Londoners down badly.”
According to figures released by the Mayor’s office, the number of late night tube journeys is increasing at double the rate of daytime times and demand for travel on night buses has risen by over 170 per cent since 2000.
The average night journey time will be cut by an average of 20 minutes by the service.
