The Rail, Maritime and Transport (RMT) union has recommended members accept a new and improved offer on the troubled Night Tube service plans.
The news represents a major breakthrough in negotiations between bosses and unions and comes after waves of strike action over implementing the service, which was originally scheduled to start last September, with a bitter war of words waged by both sides.
Other unions are involved in the dispute however and have presented a mixed reaction to the latest offer.
ASLEF, the train drivers' union, will put the deal to its executive committee on Monday 8 February. It is expected to recommend the new deal be accepted by members after its branch representatives met last week and unanimously voted in favour of taking the offer.
However Unite has requested further talks with London Underground management, and has not ruled out taking further scheduled strike action next month.
A spokesman said: 'Unite’s members have rejected the four year pay deal which was slightly improved. We represent the engineering and maintenance staff without which the 270-station network can’t function.
'Unite national officer for rail Hugh Roberts has asked for more talks with the management and we reserve the right to take action in February. But nothing is finalised as yet and we have made no announcement.
'For Unite, the pay issue and night tube is one dispute, but this is not the case for other unions.'
The The Transport Salaried Staffs' Association (TSSA) was unavailable for comment.
In a statement RMT said: 'Tube union RMT has confirmed today that it will be conducting a referendum ballot of members across London Underground over the latest offer from the company on pay and night tube.
'The ballot will open on the 11 February and the union executive is recommending acceptance of the offer.'
A spokeswoman for Transport for London said: 'Our very fair offer reiterates our previous guarantees on protecting the work-life balance of our staff and a four-year pay deal, which remains within our business plan.
'We continue to progress plans for the implementation of the Night Tube, including the recruitment of hundreds of new staff to operate Night Tube.'
Round-the-clock services for the Night Tube will operate on Fridays and Saturdays on five lines: the Jubilee, Victoria, and most of the Central, Northern and Piccadilly.
Basic Salary Pay Offer – 4 year pay offer
TfL said the deal consists of:
1 April 2015 An average increase on basic Salary of 2% from 1 April 2015 comprising as follows: 1% plus, a flat rate of £500 consolidated increase for all grades in recognition of our transformation to a 24-hour passenger service operation. This is an above inflation increase for 2015/16.
1 April 2016 RPI or 1%, whichever is the greater.
1 April 2017 RPI or 1%, whichever is the greater.
1 April 2018 RPI plus 0.25%, or 1% whichever is the greater
In addition to the above all Tube staff (drivers and station staff) are getting a £500 bonus for the successful introduction of Night Tube.
All station staff also get a £500 bonus for the successful implementation of the new staff model (Fit for the Future – Stations)