The Rail, Maritime & Transport (RMT) union will recommend its members accept a deal for pay and conditions on the Night Tube service.
The Night Tube service was due to launch in September, but was delayed due to strikes held by the RMT and other unions.
If the deal is accepted, it will be a major plus for Transport for London (TfL) in its plans to get the service up-and-running. RMT says its 10,000 members will vote on the deal on 11 February.
Under the proposals, workers will receive a 2% pay rise in the first year, a rise of 1% or inflation as measured by the Retail Prices Index (RPI) in the second and third years, and an RPI+0.25% or 1% pay rise in year four. Staff working on Night Tube lines - Jubilee, Victoria, Central, Northern and Piccadilly - will also receive a £500 bonus.
Members of the the RMT, Aslef and Unite unions last month revealed that they would hold three 24-hour strikes during February, which business leaders said would bring "chaos" back to London.
Other unions are yet to reveal whether or not they will recommend their members accept the deal, however, the Aslef union has said it is "looking like they will also accept". The Unite union has said it wants to hold further talks over the deal.
But if the RMT members were to vote to accept the deal, it would be a big step forward for TfL. One union accepting the deal would likely put pressure on the others to accept as well.