The threat of a strike by fuel tanker drivers in a dispute over terms and conditions and safety standards is set to come a step closer when the result of an industrial action ballot is announced.
Around 2,000 members of Unite at seven companies have been voting on whether to launch the first national campaign of action for over a decade.
Unite drivers supply fuel to 90% of the UK's forecourts and the union said a strike could close up to 7,900 petrol stations.
Workers in seven major distribution companies were balloted for industrial action - Wincanton, DHL, Hoyer, BP, J.W Suckling, Norbert Dentressangle and Turners.
It is likely that a yes vote will be returned, but Unite is unlikely to name any strike dates until it has held meetings with local union reps over the next few days.
The Government has announced that soldiers are being lined up to stand in for the tanker drivers if strikes go ahead.
Cabinet Office minister Francis Maude said the Government had "learnt the lessons" of the past and stood "ready to act" if stoppages go ahead.
Mr Maude said: "We are calling on the trade union Unite and the employers involved to work together to reach an agreement that will avert industrial action. Widespread strike action affecting fuel supply at our supermarkets, garages and airports could cause disruption across the country."
Jon Trickett, Labour's Shadow Minister for the Cabinet Office, said: "It is essential that a strike is averted. The Government should get a grip and show that it understands the gravity of current situation. They should immediately insist that both sides begin negotiations as every second's delay is a wasted opportunity and a moment lost."