The start of Night Tube is still months away and may not even happen until after the London Mayoral election on May 5, unions have warned.

The RMT this week became the last of the unions to call off a 24-hour strike due to begin yesterday.

Finn Brennan, London Underground organiser for Aslef, the train drivers’ union told the Evening Standard: “We could still be months away from a start for Night Tube.

“We hope the progress that’s been made means that London will finally get a Night Tube service this year.”

He blamed London Underground for the delay. “If LU had been ready to negotiate a fair agreement from the start, then the delay and two days of strike action (last year) could have been avoided.

“Let’s hope they learn the lesson for the future.”

The service was due to come into force in September last year but has been repeatedly delayed.