The Night Tube service, which was due to launch on September 12, will be delayed until next year, unions have warned.
Talks to resolve the dispute between rail unions and London Underground over pay and conditions have broken down without agreement.
The 24-hour weekend service on key lines, including the Jubilee, was the subject of industrial action earlier in the year with four rail unions co-ordinating their action for the first time.
Before the September postponement the Mayor of London had backed away from a firm date but insisted that the launch would come in the autumn. However, RMT union boss Mick Cash claims: "Boris Johnson has rung his officials from Japan and instructed them to kick the Night Tube into next year."
Across the night network owl logos have started appearing, indicating that preparations were under way, and LU has said that the 24-hour service is important to keep London growing.
• Also online: 'Night Tube will only benefit the rich'
But Finn Brennan, from drivers' union Aslef, said on Wednesday (October 14): "We have made it clear to London Underground that we want to keep talking and develop a solution that delivers the Night Tube while protecting and improving work life balance for our members.
"We have put forward a number of proposals to resolve this dispute in a way that is fair and benefits both sides.
"London Underground have rejected them all. ([They] have completely mishandled these negotiations. They have wasted every opportunity for a settlement and seem to have been determined to provoke confrontation rather than resolution."
Mr Cash added: "This crisis management of the Night Tube could have been avoided if LU hadn't chosen to try and railroad through imposed rosters and had stuck to the agreed negotiating framework from the off.
"No one wins from this situation - neither Londoners or Tube staff. RMT supports the principle of a Night Tube with properly agreed reward and rosters and the union remains available for further constructive talks."
LU have not yet commented but in the past have said it has offered more money and more assurances that no union member's quality of life would suffer. It is a 'fair and generous offer', says Mr Johnson.