The threat of a tube strike on Wednesday moved a step closer this afternoon when union officials rejected the latest offer from London Underground.
Train drivers were offered £200 a shift to work on the new 'Night Tube' in a bid to halt the threatened walkout.
The new bonus, set to last up to a year, replaced a £2,000 lump sum.
All workers on Night Tube lines, including drivers, will also get a one-off payment of £500.
London Underground said the revised offer to drivers would allow staff to pick and choose which night shifts they work.
Drivers who work more than 10 shifts could pick up in excess of £2,000 while staff who refuse to work nights would get no extra payments.
But officials from four unions, RMT, Aslef, TSSA and Unite told managers the deal was not good enough.
They gave their response to the proposal in a fresh round of talks at the conciliation service ACAS.
The unions are demanding further guarantees about the number of weekend shifts proposed in the new rosters.