There was a renewed threat of strikes by fuel tanker drivers after they "overwhelmingly rejected" proposals aimed at averting industrial action, the union Unite said.
Unite's Diana Holland said in a news conference that while "important progress on health, safety and training" had been made, the drivers needed "more guarantees and assurances from the employers about their commitment to meaningful minimum standards".
The union added that they would now approach conciliation service Acas for their assistance with further talks with employers in a bid to avert industrial action.
About 60 representatives of drivers at seven haulage firms have been discussing proposals drawn up during six days of negotiations at the conciliation service Acas.
The dispute is over a series of issues including terms and conditions, pensions and health and safety and flared up last month after Unite announced that drivers in five companies had backed strikes.
Acas said they were "disappointed" by the rejection of the deal.
The union will have to name strike dates - or other forms of industrial action - by Friday afternoon unless employers agree to extend the deadline. Seven days notice must be given if strike action is taken.
There were chaotic scenes at garages as long queues built up, leading to criticism of the Government for the way they had handled the dispute.
The AA have urged people not to panic buy fuel after today's announcement.
The Government added their disappointment at the failure of a deal and maintained that any strike action would be "wrong and unnecessary".
Hoyer, one of the firms involved in the dispute, said the rejection of the deal was a "serious blow".