A strike by fuel tankers looked increasingly likely last night after union officials voted against a proposed deal and urged their members to do the same.
The proposal was put together through Acas, the industrial mediation service, but was rejected by Unite officials, who declared it fell short of what was needed.
Their refusal to back the plan raises the spectre of fuel shortages and queues at petrol stations worse than those prompted recently when the Government advised motorists to hoard fuel.
Union delegates recognised good progress had been made in addressing health, safety and training concerns but that more improvements are needed in pensions, security of employment, contracting and sub-contracting if they are to back a deal.
The proposal is now to be put before more than 2,000 tanker drivers working for seven fuel oil distribution companies with the union recommending that they reject it.
Diana Holland, Unite's assistant general secretary, said: "The proposals represent progress on some of the key areas. But it is clear that they do not give enough guarantees that the instability and insecurity gripping the industry will come to an end.
"It is in everyone's interest that we end the contract merry-go-round and the erosion of standards. Delegates felt the proposals did not meet members' expectations and are recommending that members reject them in the consultative ballot." The ballot is expected to close on 11 May.
The announcement came as ballot papers were sent out to more than 530 tanker drivers working for the oil distribution firm Hoyer. Unite is re-balloting its members following concerns that some did not receive voting papers in the original ballot.