Dunedin: New Zealand has been hit by a severe shortage of jet fuel, with thousands of domestic and international passengers stranded after a digger struck an airport supply pipe in Auckland, the country’s biggest city.

International and domestic flights have been affected, with airlines told to fill plane tanks to capacity in other domestic airports before flying to Auckland, and long-haul international flights told to plan for re-fuelling stops in Australia and the Pacific Islands, according to Air New Zealand. The airline predicted about 2,000 passengers a day would be affected.

Jet fuel is being rationed in Auckland after the farm digger struck the sole supply pipe on Thursday, reducing jet fuel supplies to 30 per cent of normal capacity. Petrol and diesel supplies have also been affected by the damaged pipe, with both fuels being driven overland to Auckland from other supply points in the North Island.

Energy minister Judith Collins said the military could be called on to assist with fuel transportation overland if needed.

“The pipeline is the only source of jet fuel for Auckland airport, so precautions have been taken to restrict the amount of fuel being used,” said Collins, who added it was unlikely the petrol and diesel shortages would affect motorists in Auckland, home to 1.4 million people.

“Refining NZ has all the expert technical assistance resources it needs, including international expertise. I have also offered them, and the companies supplying fuel, government assistance, if we are needed.”

The leak in the Northland refinery was shut off within 15 minutes of being hit but 70,000 litres of fuel was lost during the incident.

Refining NZ — which supplies all of New Zealand’s jet fuel — has estimated it could take 10-15 days to fix the broken pipe, at a cost of up to $NZ15 million (Dh40.24 million), but the environmental impact of the leak had been “contained”.

A 2012 report from the Ministry of Business, Innovation and Employment said a major disruption to the Auckland jet fuel supply could cost New Zealand NZ$400-500 million in lost export and tourism dollars, and truck drivers might need to be brought in from Australia to assist with overland transportation.

However deputy prime minister Paula Bennett told Radio NZ she was confident the shortage would not affect New Zealand’s attraction as a prime tourist destination, despite tourism companies already reporting worried calls from overseas customers.

“I think that people will see this as a very rare occurrence, it hasn’t happened for 30 years, we don’t expect it to happen again,” she said. “It’s private business that owns that line, and you would expect them to have a better contingency plans, so we will go and look at that and get it right.”

The National party said its final week of election campaigning would not be affected by the fuel shortage because the campaign team was using a bus. The opposition Labour Party said its travel plans had not yet been disrupted, but “we are closely watching the situation”.

Labour leader Jacinda Ardern criticised the government’s lack of investment in key infrastructure and said it had “serious questions” to answer over the fuel crisis.

“The government has known for years that there were risks to the security of supply of fuel into Auckland, and particularly jet fuel to Auckland airport. And they have only got worse as the city grows and air traffic expands,” Ardern said in a statement.

“We just can’t afford to cut corners on infrastructure — and yet we have seen National take this approach on others issues, too. They have failed to invest adequately in Auckland’s transport infrastructure, dragged the chain on the city’s Central Rail Link while running down our public infrastructure such as hospitals and schools.”

The Green party called the fuel leak a “debacle” and demanded the Northland regional council and Refining NZ release scientific evidence to prove no environmental damage had occurred.

“Even if contaminated soil has been removed, further excavation of the wetland could be needed. This could have implications for the water table in the wetland, water quality and native wildlife,” it said in a statement.