Hoyer said it had a responsibility not to give its tanker drivers “unsustainable increases” in their salary after the Unite union threatened strike action in a row over pay.

The logistics company said it had already made drivers at the Grangemouth oil terminal an offer in excess of 14% and their pay was already far in excess of UK average salary rates.

It added that negotiations were ongoing but that it was also working on contingency plans to avoid disruption to fuel supplies across Scotland if industrial action went ahead.

However, Unite said over 30 members employed by Hoyer Gas and Petroleum Logistics backed strike action by 100% on a 97% turnout, after the membership rejected a 7% pay offer.

It also claimed that Hoyer’s current offer did nothing to bring drivers into line with industry standards, including the pay levels of other Hoyer drivers based out of Grangemouth.

“Unite’s Hoyer tanker drivers are simply seeking a fair day’s pay,” said the union’s general secretary Sharon Graham.

“There is no reason why Hoyer can’t pay these drivers a higher rate. They are doing exactly the same job for the company but they are being paid significantly below other Hoyer drivers based out of the Grangemouth oil terminal.”

Unite said businesses impacted by any strike action included BP and Air BP, Esso and World Fuels Services (Aviation), which provided aviation fuel transport to Edinburgh, Glasgow, Aberdeen and Newcastle airports.

But Hoyer said it would continue to try and resolve the situation: “During the negotiations so far we have made our drivers at Grangemouth an offer in excess of 14%, well above both the rate of inflation and current levels of earnings increases across all sectors,” said a Hoyer spokeswoman.

“Our Grangemouth drivers’ pay is already far in excess of average salary rates in the UK and, given that we remain in a cost of living crisis and further cost rises will inevitably reach British motorists at the pump, we have a general responsibility not to offer unsustainable increases.

“In the meantime, we will continue to negotiate with the Union in good faith whilst simultaneously working on contingency plans to mitigate any disruption should industrial action proceed.”