TALKS have failed to avert a 24-hour Tube strike on Wednesday evening.
London Underground (LU) bosses have been meeting delegates from four unions representing 20,000 workers but the unions said no deal had been reached.
The Rail, Maritime and Transport union (RMT), Transport Salaried Staffs Association (TSSA), and Unite members plan to walk out at 18:30 BST.
Aslef drivers will begin strike action from 21:30 BST. No further negotiations are planned, according to RMT.
LU and the unions had been trying to reach a deal on Tuesday over the introduction of the new night Tube service.
Mick Cash, RMT general secretary, said: "Despite strenuous efforts by union negotiators to press London Underground to address the issues of fairness, safety, work-life balance and equality at the heart of this dispute, they have come up with nothing in the talks this afternoon."
He said the "action is on" and "there are no further talks planned at this stage".
Transport for London (TfL) said extra bus and river services would be run on Thursday, but warned that roads and all public transport would be much busier than usual.
