The service, which will run on Friday nights and the early hours of Saturday and Sunday mornings on five lines, was originally due to start in September.
City Hall says it would make getting home after a night out easier and cheaper and has suggested the service could help boost London’s night-time economy by up to £360 million.
Plans to extend the Tube’s opening hours were first announced in November 2013 by Mayor Johnson and then Tube boss Mike Brown, now Transport Commissioner, despite London Underground not having reached agreement with unions about changes to pay and working conditions for staff being asked to work later shifts.
Unions say LU were wrong to expect existing staff to work beyond their current contracted hours, complaining that this would have an adverse impact on their work-life balance.
Although LU has offered a number of modified pay deals, the two sides have failed to resolve their differences leading to a series of strikes by members of Aslef, the RMT and TSSA union.
Failure to reach agreement with the unions forced Tube managers to suspend plans for the service which currently has no official start date.
LU recently advertised for 200 part-time drivers, saying the new recruits meant existing staff wouldn’t work longer hours “unless they want to”.
However the BBC today reported that Aslef and the RMT are considering plans for further strikes following the “total breakdown of negotiations” between them and Tube bosses.
An internal Aslef document seen by the BBC reportedly says: “We genuinely regret the inconvenience that will be caused but the behaviour of London Underground’s senior management team have left us with no other choice.
“We want to see an all-night service introduced and we are not opposed to the recruitment of part-time staff but we will not accept a zero-hours culture being introduced and working conditions undermined.”
Following the BBC’s report, Mayor Johnson said it was “unbelievable” that unions were considering further industrial action.
He insisted they had been offered “excellent” terms for staff to be a part of the new service and accused them of making “outrageous demands” including seeking to impose “a new four-day week, which would have been completely unaffordable for TfL and for London’s fare payers.”
Mr Johnson said “roughly 6,400” people had applied for the 200 new part-time posts, claiming that “managers have been overwhelmed by the response” and vowed that the new drivers meant London “will get the 24 hour night service it needs, with or without the help of Aslef.”
The Mayor’s comments were backed up by Steve Griffiths, Chief Operating Officer for London Underground, who accused the unions of “trying everything to stop the Night Tube”.
Mr Griffiths added: “The truth is that they are making excessive demands for more money, fewer hours and a four day week and expect fare and tax payers to pick up the bill. That is the real reason they plan to disrupt Londoners.
“No employer could possibly meet such demands and strike action will change nothing. There is no more money.”
Today’s reports have also provoked comment from Tory mayoral candidate Zac Goldsmith who seized on the opportunity to take a swipe at Labour rival Sadiq Khan whose City Hall bid has been endorsed by Aslef and the TSSA.
The Tory candidate has been calling for stricter thresholds for strike action on Transport for London services and said the prospect of further disruption proved the need for a Mayor who was “independent of the trade unions”.
He added: “It is simply unacceptable that unions can still be allowed to use strikes for political purposes. Strikes hit businesses hard and those on low wages and part time contracts even harder. And all for the bragging rights of union bosses.
“Enough is enough. I’ll stand up for all those who aren’t interested in union games and just want to get to work and go about their lives without disruption.
“It’s why the election on 5th May matters so much – we can expect four years of these games and gridlock if Sadiq Khan and his union paymasters get their way.”
Liberal Democrat Mayoral candidate Caroline Pidgeon said Mr Johnson and TfL “have messed up this negotiation by giving an artificial deadline for the start of the night tube, allowing the Unions to hold them to ransom.”
She added: “But given that date passed last September, it is quite clear that the Unions are now playing games rather than working all out to secure an agreement. Both sides need to come together, sit round the table and hammer out a full and fair deal. Londoners need, and expect, nothing less.”
