Night Tube: RMT union members agree pay and conditions offer
A pay and conditions deal over the Night Tube service has been accepted by members of the Rail, Maritime and Transport (RMT) union.
The union said 84% of its 10,000 members voted in favour of the offer, described by the RMT as a "fair deal".
Three other unions are still to decide whether they will accept the offer, described by London Underground (LU) as "fair and affordable".
The service was meant to begin in September last year.
RMT General Secretary Mick Cash said the agreement had come about because of the "loyalty, determination and militancy of the workforce right across the Tube network".
Steve Griffiths, LU chief operating officer, said he was "pleased" RMT members had accepted the deal.
Analysis by BBC London transport correspondent Tom Edwards
It wasn't really a surprise but it is still another big step towards the Night Tube.
Eighty-four percent of RMT Tube members voted to accept the four-year above-inflation pay deal and a £500 bonus - but three other unions have yet to decide.
Timescales are still unclear. One hundred-and-eighty part-time drivers will have to be trained up and that could take months, but you might see a Night Tube launch by the summer.
It's feasible you might get a trial before that but after being burnt with the original start date of last September, transport bosses will be treading carefully.
The proposed agreement includes a 2% pay rise in year one, Retail Prices Index (RPI) inflation or 1% (whichever is greater) in years two and three, and RPI plus 0.25% or 1% (whichever is greater) in year four.
There will also be a £500 bonus for staff on lines where the Night Tube will run.
Members of the drivers' union Aslef are currently voting on the offer with the result expected on 7 March.
The TSSA and Unite have yet to put the offer to their members.
TfL said it was "seeking agreement with the other unions" and was focussing on "recruiting staff to deliver the Night Tube for London as quickly as possible".