There is "not enough common ground" between London Underground and the trade unions planning to strike on 8 and 9 July to suspend the industrial action, a source close to the negotiations has told IBTimes UK.
Finn Brennan, a district organiser for Aslef, said: "Clearly there will have to be meetings going forward, but there's not enough common ground between the two sides for the dispute to be resolved today."
The union official also blasted London Underground management for their "absolutely bizarre and disingenuous" negotiating tactics during their meetings at conciliation service Acas.
London Underground management had offered to increase tube workers' pay packets by 2% in 2015 and give a £2,000 ($3,079) "transition bonus" to drivers on the new night Tube service.
But union negotiators failed to accept the offer by the extended deadline of 22:00 (originally 18.30) on 6 July.
The Mayor of London Boris Johnson took to the airwaves this morning (8 July) and blamed the unions for not taking the proposal to their members.
"The reason we are having this industrial action is because we are having the guts and the balls, frankly, to go ahead with some difficult changes," he told LBC Radio.
"The vast majority of tube workers do an incredible job. It's perfectly obvious what's going on – this is a good offer that we have made to the union leadership and they have not got back to us. They owe it to their members to put it to their members and get back to us."
But Brennan hit back and claimed the Conservatives were billing the dispute as a political row in a bid to "distract from the incompetent way in which London Underground handled the negotiations".
He made reference to an opinion piece by Patrick McLoughlin, the transport secretary, in the Evening Standard. McLoughlin claimed that the unions were "planning to pull the plug on the Tube in a needless strike that's all about politics".
Brennan said: "It's clearly a line from Tory central office that the transport minister was peddling yesterday – that this is a political dispute. That is absolute nonsense: it's an industrial dispute. They are putting forward the argument that it is political to distract from the incompetent way in which London Underground handled the negotiations."
London Underground open to talks
Meanwhile, a Transport Salaried Staffs Association (TSSA) spokesman told IBTimes UK that there was a 95% chance of a walkout today but that he was "not ruling out talks".
The Rail, Maritime and Transport union (RMT), Unite, and other unions involved in the walk-out did not responded to a request for comment at the time of publication.
The strike is expected to go ahead at 18.30 today (8 July) for 24 hours with around 20,000 workers walking out. Transport for London said around 200 extra buses will be put on during the industrial action to help commuters get around.
Steve Griffiths, London Underground's Chief Operating Officer, said management are available for talks at Acas "all day".
"Londoners and businesses overwhelmingly back the Night Tube. It will make life better for everyone, cut journey times, create jobs and boost the economy. Many of our staff will not be affected by the new services, as we are operating Friday and Saturday night services on five lines. We are also hiring 137 more train operators specifically to work on the Night Tube. For those who are affected, it will mean a few extra nights per year within the existing working week," said Griffiths.
"No-one is being asked to work more hours than they do now. In return, we have offered a very fair and competitive package of an average 2% increase this year, a pay increase of Retail Price Index (RPI) inflation or 1%, whichever is greater, in 2016 and 2017, a £500 launch bonus to all staff on the Night Tube lines and stations, and a £2,000 transition bonus for train operators. We received no response to this from the union leaderships."