An all-night Tube service will not be introduced this year after talks broke down between unions and bosses, it has been reported.
When London Underground first announced plans for the Night Tube it was scheduled to begin in September 2015, but the start date was pushed back amid acrimonious row over pay and conditions.
Union sources told the Press Association that another meeting held on Wednesday had failed to resolve the deadlock, and talks have now broken up without agreement.
The news is a blow for Boris Johnson, the London Mayor, who has previously tried to play down the importance of the start date as long as it came "before the end of autumn". Union bosses said that specification would definitely not be met now.
In a statement, Finn Brennan from the train drivers' union, Aslef, said: "We have made it clear to London Underground that we want to keep talking and develop a solution that delivers 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. Most disappointingly of all they have decided to blackmail their own employees by refusing to make a pay offer unless staff agree to worsen their working conditions.
"That is not something we are prepared to accept. Underground management 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."
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies