Tube Union leaders today demanded Boris Johnson postpone the launch of his flagship 24-hour Underground service.
The 'Night Tube', operating on five lines on Friday and Saturday nights, is due to start on September 12th.
But the unions have refused to accept new rosters and extra payments including £200 a shift for drivers who work on the Night Tube.
A strike by members of four unions, RMT, Aslef, TSSA and Unite, is expected to bring the Underground to a standstill tomorrow evening.
Services are likely to become erratic from 6.30pm with no trains after 9.30pm. The Underground is expected to remain closed throughout Thursday.
Negotiations at the conciliation service ACAS broke down without agreement yesterday. No further talks are likely until next week.
The RMT claimed the Night Tube was 'fundamentally flawed' and should be postponed indefinitely.